5
This document describes the Bazaar internals and the development process.
6
It's meant for people interested in developing Bazaar, and some parts will
7
also be useful to people developing Bazaar plugins.
9
If you have any questions or something seems to be incorrect, unclear or
10
missing, please talk to us in ``irc://irc.freenode.net/#bzr``, or write to
11
the Bazaar mailing list. To propose a correction or addition to this
12
document, send a merge request or new text to the mailing list.
14
The latest developer documentation can be found online at
15
http://doc.bazaar-vcs.org/developers/.
21
Exploring the Bazaar Platform
22
=============================
24
Before making changes, it's a good idea to explore the work already
25
done by others. Perhaps the new feature or improvement you're looking
26
for is available in another plug-in already? If you find a bug,
27
perhaps someone else has already fixed it?
29
To answer these questions and more, take a moment to explore the
30
overall Bazaar Platform. Here are some links to browse:
32
* The Plugins page on the Wiki - http://bazaar-vcs.org/BzrPlugins
34
* The Bazaar product family on Launchpad - https://launchpad.net/bazaar
36
* Bug Tracker for the core product - https://bugs.launchpad.net/bzr/
38
* Blueprint Tracker for the core product - https://blueprints.launchpad.net/bzr/
40
If nothing else, perhaps you'll find inspiration in how other developers
41
have solved their challenges.
43
Finding Something To Do
44
=======================
46
Ad-hoc performance work can also be done. One useful tool is the 'evil' debug
47
flag. For instance running ``bzr -Devil commit -m "test"`` will log a backtrace
48
to the bzr log file for every method call which triggers a slow or non-scalable
49
part of the bzr library. So checking that a given command with ``-Devil`` has
50
no backtraces logged to the log file is a good way to find problem function
51
calls that might be nested deep in the code base.
53
Planning and Discussing Changes
54
===============================
56
There is a very active community around Bazaar. Mostly we meet on IRC
57
(#bzr on irc.freenode.net) and on the mailing list. To join the Bazaar
58
community, see http://bazaar-vcs.org/BzrSupport.
60
If you are planning to make a change, it's a very good idea to mention it
61
on the IRC channel and/or on the mailing list. There are many advantages
62
to involving the community before you spend much time on a change.
65
* you get to build on the wisdom on others, saving time
67
* if others can direct you to similar code, it minimises the work to be done
69
* it assists everyone in coordinating direction, priorities and effort.
71
In summary, maximising the input from others typically minimises the
72
total effort required to get your changes merged. The community is
73
friendly, helpful and always keen to welcome newcomers.
76
Bazaar Development in a Nutshell
77
================================
79
.. was from bazaar-vcs.org/BzrGivingBack
81
One of the fun things about working on a version control system like Bazaar is
82
that the users have a high level of proficiency in contributing back into
83
the tool. Consider the following very brief introduction to contributing back
84
to Bazaar. More detailed instructions are in the following sections.
89
First, get a local copy of the development mainline (See `Why make a local
95
$ bzr branch http://bazaar-vcs.org/bzr/bzr.dev/ bzr.dev
97
Now make your own branch::
99
$ bzr branch bzr.dev 123456-my-bugfix
101
This will give you a branch called "123456-my-bugfix" that you can work on
102
and commit in. Here, you can study the code, make a fix or a new feature.
103
Feel free to commit early and often (after all, it's your branch!).
105
Documentation improvements are an easy place to get started giving back to the
106
Bazaar project. The documentation is in the `doc/` subdirectory of the Bazaar
109
When you are done, make sure that you commit your last set of changes as well!
110
Once you are happy with your changes, ask for them to be merged, as described
113
Making a Merge Proposal
114
-----------------------
116
The Bazaar developers use Launchpad to further enable a truly distributed
117
style of development. Anyone can propose a branch for merging into the Bazaar
118
trunk. To start this process, you need to push your branch to Launchpad. To
119
do this, you will need a Launchpad account and user name, e.g.
120
`your_lp_username`. You can push your branch to Launchpad directly from
123
$ bzr push lp:~your_lp_username/bzr/giveback
125
After you have pushed your branch, you will need to propose it for merging to
126
the Bazaar trunk. Go to <https://launchpad.net/your_lp_username/bzr/giveback>
127
and choose "Propose for merging into another branch". Select "~bzr/bzr/trunk"
128
to hand your changes off to the Bazaar developers for review and merging.
130
Why make a local copy of bzr.dev?
131
---------------------------------
133
Making a local mirror of bzr.dev is not strictly necessary, but it means
135
- You can use that copy of bzr.dev as your main bzr executable, and keep it
136
up-to-date using ``bzr pull``.
137
- Certain operations are faster, and can be done when offline. For example:
140
- ``bzr diff -r ancestor:...``
143
- When it's time to create your next branch, it's more convenient. When you
144
have further contributions to make, you should do them in their own branch::
147
$ bzr branch bzr.dev additional_fixes
148
$ cd additional_fixes # hack, hack, hack
152
Understanding the Development Process
153
=====================================
155
The development team follows many practices including:
157
* a public roadmap and planning process in which anyone can participate
159
* time based milestones everyone can work towards and plan around
161
* extensive code review and feedback to contributors
163
* complete and rigorous test coverage on any code contributed
165
* automated validation that all tests still pass before code is merged
166
into the main code branch.
168
The key tools we use to enable these practices are:
170
* Launchpad - https://launchpad.net/
172
* Bazaar - http://bazaar-vcs.org/
174
* Bundle Buggy - http://bundlebuggy.aaronbentley.com/
176
* Patch Queue Manager - https://launchpad.net/pqm/
178
For further information, see http://bazaar-vcs.org/BzrDevelopment.
183
Preparing a Sandbox for Making Changes to Bazaar
184
================================================
186
Bazaar supports many ways of organising your work. See
187
http://bazaar-vcs.org/SharedRepositoryLayouts for a summary of the
188
popular alternatives.
190
Of course, the best choice for you will depend on numerous factors:
191
the number of changes you may be making, the complexity of the changes, etc.
192
As a starting suggestion though:
194
* create a local copy of the main development branch (bzr.dev) by using
197
bzr branch http://bazaar-vcs.org/bzr/bzr.dev/ bzr.dev
199
* keep your copy of bzr.dev pristine (by not developing in it) and keep
200
it up to date (by using bzr pull)
202
* create a new branch off your local bzr.dev copy for each issue
203
(bug or feature) you are working on.
205
This approach makes it easy to go back and make any required changes
206
after a code review. Resubmitting the change is then simple with no
207
risk of accidentally including edits related to other issues you may
208
be working on. After the changes for an issue are accepted and merged,
209
the associated branch can be deleted or archived as you wish.
212
Navigating the Code Base
213
========================
215
.. Was at <http://bazaar-vcs.org/NewDeveloperIntroduction>
217
Some of the key files in this directory are:
220
The command you run to start Bazaar itself. This script is pretty
221
short and just does some checks then jumps into bzrlib.
224
This file covers a brief introduction to Bazaar and lists some of its
228
Summary of changes in each Bazaar release that can affect users or
232
Installs Bazaar system-wide or to your home directory. To perform
233
development work on Bazaar it is not required to run this file - you
234
can simply run the bzr command from the top level directory of your
235
development copy. Note: That if you run setup.py this will create a
236
'build' directory in your development branch. There's nothing wrong
237
with this but don't be confused by it. The build process puts a copy
238
of the main code base into this build directory, along with some other
239
files. You don't need to go in here for anything discussed in this
243
Possibly the most exciting folder of all, bzrlib holds the main code
244
base. This is where you will go to edit python files and contribute to
248
Holds documentation on a whole range of things on Bazaar from the
249
origination of ideas within the project to information on Bazaar
250
features and use cases. Within this directory there is a subdirectory
251
for each translation into a human language. All the documentation
252
is in the ReStructuredText markup language.
255
Documentation specifically targeted at Bazaar and plugin developers.
256
(Including this document.)
260
Automatically-generated API reference information is available at
261
<http://starship.python.net/crew/mwh/bzrlibapi/>.
263
See also the :doc:`Bazaar Architectural Overview <overview>`.
266
The Code Review Process
267
#######################
269
All code changes coming in to Bazaar are reviewed by someone else.
270
Normally changes by core contributors are reviewed by one other core
271
developer, and changes from other people are reviewed by two core
272
developers. Use intelligent discretion if the patch is trivial.
274
Good reviews do take time. They also regularly require a solid
275
understanding of the overall code base. In practice, this means a small
276
number of people often have a large review burden - with knowledge comes
277
responsibility. No one likes their merge requests sitting in a queue going
278
nowhere, so reviewing sooner rather than later is strongly encouraged.
287
Please put a "cover letter" on your merge request explaining:
289
* the reason **why** you're making this change
291
* **how** this change achieves this purpose
293
* anything else you may have fixed in passing
295
* anything significant that you thought of doing, such as a more
296
extensive fix or a different approach, but didn't or couldn't do now
298
A good cover letter makes reviewers' lives easier because they can decide
299
from the letter whether they agree with the purpose and approach, and then
300
assess whether the patch actually does what the cover letter says.
301
Explaining any "drive-by fixes" or roads not taken may also avoid queries
302
from the reviewer. All in all this should give faster and better reviews.
303
Sometimes writing the cover letter helps the submitter realize something
304
else they need to do. The size of the cover letter should be proportional
305
to the size and complexity of the patch.
308
Reviewing proposed changes
309
==========================
311
Anyone is welcome to review code, and reply to the thread with their
314
The simplest way to review a proposed change is to just read the patch on
315
the list or in Bundle Buggy. For more complex changes it may be useful
316
to make a new working tree or branch from trunk, and merge the proposed
317
change into it, so you can experiment with the code or look at a wider
320
There are three main requirements for code to get in:
322
* Doesn't reduce test coverage: if it adds new methods or commands,
323
there should be tests for them. There is a good test framework
324
and plenty of examples to crib from, but if you are having trouble
325
working out how to test something feel free to post a draft patch
328
* Doesn't reduce design clarity, such as by entangling objects
329
we're trying to separate. This is mostly something the more
330
experienced reviewers need to help check.
332
* Improves bugs, features, speed, or code simplicity.
334
Code that goes in should not degrade any of these aspects. Patches are
335
welcome that only cleanup the code without changing the external
336
behaviour. The core developers take care to keep the code quality high
337
and understandable while recognising that perfect is sometimes the enemy
340
It is easy for reviews to make people notice other things which should be
341
fixed but those things should not hold up the original fix being accepted.
342
New things can easily be recorded in the Bug Tracker instead.
344
It's normally much easier to review several smaller patches than one large
345
one. You might want to use ``bzr-loom`` to maintain threads of related
346
work, or submit a preparatory patch that will make your "real" change
350
Checklist for reviewers
351
=======================
353
* Do you understand what the code's doing and why?
355
* Will it perform reasonably for large inputs, both in memory size and
356
run time? Are there some scenarios where performance should be
359
* Is it tested, and are the tests at the right level? Are there both
360
blackbox (command-line level) and API-oriented tests?
362
* If this change will be visible to end users or API users, is it
363
appropriately documented in NEWS?
365
* Does it meet the coding standards below?
367
* If it changes the user-visible behaviour, does it update the help
368
strings and user documentation?
370
* If it adds a new major concept or standard practice, does it update the
371
developer documentation?
373
* (your ideas here...)
379
From May 2009 on, we prefer people to propose code reviews through
382
* <https://launchpad.net/+tour/code-review>
384
* <https://help.launchpad.net/Code/Review>
386
Anyone can propose or comment on a merge proposal just by creating a
389
There are two ways to create a new merge proposal: through the web
390
interface or by email.
393
Proposing a merge through the web
394
---------------------------------
396
To create the proposal through the web, first push your branch to Launchpad.
397
For example, a branch dealing with documentation belonging to the Launchpad
398
User mbp could be pushed as ::
400
bzr push lp:~mbp/bzr/doc
402
Then go to the branch's web page, which in this case would be
403
<https://code.launchpad.net/~mbp/bzr/doc>. You can simplify this step by just
408
You can then click "Propose for merging into another branch", and enter your
409
cover letter (see above) into the web form. Typically you'll want to merge
410
into ``~bzr/bzr/trunk`` which will be the default; you might also want to
411
nominate merging into a release branch for a bug fix. There is the option to
412
specify a specific reviewer or type of review, and you shouldn't normally
415
Submitting the form takes you to the new page about the merge proposal
416
containing the diff of the changes, comments by interested people, and
417
controls to comment or vote on the change.
419
Proposing a merge by mail
420
-------------------------
422
To propose a merge by mail, send a bundle to ``merge@code.launchpad.net``.
424
You can generate a merge request like this::
426
bzr send -o bug-1234.diff
428
``bzr send`` can also send mail directly if you prefer; see the help.
433
From <https://code.launchpad.net/bzr/+activereviews> you can see all
434
currently active reviews, and choose one to comment on. This page also
435
shows proposals that are now approved and should be merged by someone with
439
Reviews through Bundle Buggy
440
============================
442
The Bundle Buggy tool used up to May 2009 is still available as a review
445
Sending patches for review
446
--------------------------
448
If you'd like to propose a change, please post to the
449
bazaar@lists.canonical.com list with a bundle, patch, or link to a
450
branch. Put ``[PATCH]`` or ``[MERGE]`` in the subject so Bundle Buggy
451
can pick it out, and explain the change in the email message text.
452
Remember to update the NEWS file as part of your change if it makes any
453
changes visible to users or plugin developers. Please include a diff
454
against mainline if you're giving a link to a branch.
456
You can generate a merge request like this::
458
bzr send -o bug-1234.patch
460
A ``.patch`` extension is recommended instead of .bundle as many mail clients
461
will send the latter as a binary file.
463
``bzr send`` can also send mail directly if you prefer; see the help.
465
Please do **NOT** put [PATCH] or [MERGE] in the subject line if you don't
466
want it to be merged. If you want comments from developers rather than
467
to be merged, you can put ``[RFC]`` in the subject line.
469
If this change addresses a bug, please put the bug number in the subject
470
line too, in the form ``[#1]`` so that Bundle Buggy can recognize it.
472
If the change is intended for a particular release mark that in the
473
subject too, e.g. ``[1.6]``.
474
Anyone can "vote" on the mailing list by expressing an opinion. Core
475
developers can also vote using Bundle Buggy. Here are the voting codes and
478
:approve: Reviewer wants this submission merged.
479
:tweak: Reviewer wants this submission merged with small changes. (No
481
:abstain: Reviewer does not intend to vote on this patch.
482
:resubmit: Please make changes and resubmit for review.
483
:reject: Reviewer doesn't want this kind of change merged.
484
:comment: Not really a vote. Reviewer just wants to comment, for now.
486
If a change gets two approvals from core reviewers, and no rejections,
487
then it's OK to come in. Any of the core developers can bring it into the
488
bzr.dev trunk and backport it to maintenance branches if required. The
489
Release Manager will merge the change into the branch for a pending
490
release, if any. As a guideline, core developers usually merge their own
491
changes and volunteer to merge other contributions if they were the second
492
reviewer to agree to a change.
494
To track the progress of proposed changes, use Bundle Buggy. See
495
http://bundlebuggy.aaronbentley.com/help for a link to all the
496
outstanding merge requests together with an explanation of the columns.
497
Bundle Buggy will also mail you a link to track just your change.
499
Coding Style Guidelines
500
#######################
505
``hasattr`` should not be used because it swallows exceptions including
506
``KeyboardInterrupt``. Instead, say something like ::
508
if getattr(thing, 'name', None) is None
514
Please write PEP-8__ compliant code.
516
__ http://www.python.org/peps/pep-0008.html
518
One often-missed requirement is that the first line of docstrings
519
should be a self-contained one-sentence summary.
521
We use 4 space indents for blocks, and never use tab characters. (In vim,
524
Trailing white space should be avoided, but is allowed.
525
You should however not make lots of unrelated white space changes.
527
Unix style newlines (LF) are used.
529
Each file must have a newline at the end of it.
531
Lines should be no more than 79 characters if at all possible.
532
Lines that continue a long statement may be indented in either of
535
within the parenthesis or other character that opens the block, e.g.::
541
or indented by four spaces::
547
The first is considered clearer by some people; however it can be a bit
548
harder to maintain (e.g. when the method name changes), and it does not
549
work well if the relevant parenthesis is already far to the right. Avoid
552
self.legbone.kneebone.shinbone.toebone.shake_it(one,
558
self.legbone.kneebone.shinbone.toebone.shake_it(one,
564
self.legbone.kneebone.shinbone.toebone.shake_it(
567
For long lists, we like to add a trailing comma and put the closing
568
character on the following line. This makes it easier to add new items in
571
from bzrlib.goo import (
577
There should be spaces between function parameters, but not between the
578
keyword name and the value::
580
call(1, 3, cheese=quark)
584
;(defface my-invalid-face
585
; '((t (:background "Red" :underline t)))
586
; "Face used to highlight invalid constructs or other uglyties"
589
(defun my-python-mode-hook ()
590
;; setup preferred indentation style.
591
(setq fill-column 79)
592
(setq indent-tabs-mode nil) ; no tabs, never, I will not repeat
593
; (font-lock-add-keywords 'python-mode
594
; '(("^\\s *\t" . 'my-invalid-face) ; Leading tabs
595
; ("[ \t]+$" . 'my-invalid-face) ; Trailing spaces
596
; ("^[ \t]+$" . 'my-invalid-face)); Spaces only
600
(add-hook 'python-mode-hook 'my-python-mode-hook)
602
The lines beginning with ';' are comments. They can be activated
603
if one want to have a strong notice of some tab/space usage
610
* Imports should be done at the top-level of the file, unless there is
611
a strong reason to have them lazily loaded when a particular
612
function runs. Import statements have a cost, so try to make sure
613
they don't run inside hot functions.
615
* Module names should always be given fully-qualified,
616
i.e. ``bzrlib.hashcache`` not just ``hashcache``.
622
Functions, methods or members that are "private" to bzrlib are given
623
a leading underscore prefix. Names without a leading underscore are
624
public not just across modules but to programmers using bzrlib as an
625
API. As a consequence, a leading underscore is appropriate for names
626
exposed across modules but that are not to be exposed to bzrlib API
629
We prefer class names to be concatenated capital words (``TestCase``)
630
and variables, methods and functions to be lowercase words joined by
631
underscores (``revision_id``, ``get_revision``).
633
For the purposes of naming some names are treated as single compound
634
words: "filename", "revno".
636
Consider naming classes as nouns and functions/methods as verbs.
638
Try to avoid using abbreviations in names, because there can be
639
inconsistency if other people use the full name.
645
``revision_id`` not ``rev_id`` or ``revid``
647
Functions that transform one thing to another should be named ``x_to_y``
648
(not ``x2y`` as occurs in some old code.)
654
Python destructors (``__del__``) work differently to those of other
655
languages. In particular, bear in mind that destructors may be called
656
immediately when the object apparently becomes unreferenced, or at some
657
later time, or possibly never at all. Therefore we have restrictions on
658
what can be done inside them.
660
0. If you think you need to use a ``__del__`` method ask another
661
developer for alternatives. If you do need to use one, explain
664
1. Never rely on a ``__del__`` method running. If there is code that
665
must run, do it from a ``finally`` block instead.
667
2. Never ``import`` from inside a ``__del__`` method, or you may crash the
670
3. In some places we raise a warning from the destructor if the object
671
has not been cleaned up or closed. This is considered OK: the warning
672
may not catch every case but it's still useful sometimes.
678
In some places we have variables which point to callables that construct
679
new instances. That is to say, they can be used a lot like class objects,
680
but they shouldn't be *named* like classes:
682
> I think that things named FooBar should create instances of FooBar when
683
> called. Its plain confusing for them to do otherwise. When we have
684
> something that is going to be used as a class - that is, checked for via
685
> isinstance or other such idioms, them I would call it foo_class, so that
686
> it is clear that a callable is not sufficient. If it is only used as a
687
> factory, then yes, foo_factory is what I would use.
693
Several places in Bazaar use (or will use) a registry, which is a
694
mapping from names to objects or classes. The registry allows for
695
loading in registered code only when it's needed, and keeping
696
associated information such as a help string or description.
699
InterObject and multiple dispatch
700
=================================
702
The ``InterObject`` provides for two-way `multiple dispatch`__: matching
703
up for example a source and destination repository to find the right way
704
to transfer data between them.
706
.. __: http://en.wikipedia.org/wiki/Multiple_dispatch
708
There is a subclass ``InterObject`` classes for each type of object that is
709
dispatched this way, e.g. ``InterRepository``. Calling ``.get()`` on this
710
class will return an ``InterObject`` instance providing the best match for
711
those parameters, and this instance then has methods for operations
714
inter = InterRepository.get(source_repo, target_repo)
715
inter.fetch(revision_id)
717
``InterRepository`` also acts as a registry-like object for its
718
subclasses, and they can be added through ``.register_optimizer``. The
719
right one to run is selected by asking each class, in reverse order of
720
registration, whether it ``.is_compatible`` with the relevant objects.
725
To make startup time faster, we use the ``bzrlib.lazy_import`` module to
726
delay importing modules until they are actually used. ``lazy_import`` uses
727
the same syntax as regular python imports. So to import a few modules in a
730
from bzrlib.lazy_import import lazy_import
731
lazy_import(globals(), """
740
revision as _mod_revision,
742
import bzrlib.transport
746
At this point, all of these exist as a ``ImportReplacer`` object, ready to
747
be imported once a member is accessed. Also, when importing a module into
748
the local namespace, which is likely to clash with variable names, it is
749
recommended to prefix it as ``_mod_<module>``. This makes it clearer that
750
the variable is a module, and these object should be hidden anyway, since
751
they shouldn't be imported into other namespaces.
753
While it is possible for ``lazy_import()`` to import members of a module
754
when using the ``from module import member`` syntax, it is recommended to
755
only use that syntax to load sub modules ``from module import submodule``.
756
This is because variables and classes can frequently be used without
757
needing a sub-member for example::
759
lazy_import(globals(), """
760
from module import MyClass
764
return isinstance(x, MyClass)
766
This will incorrectly fail, because ``MyClass`` is a ``ImportReplacer``
767
object, rather than the real class.
769
It also is incorrect to assign ``ImportReplacer`` objects to other variables.
770
Because the replacer only knows about the original name, it is unable to
771
replace other variables. The ``ImportReplacer`` class will raise an
772
``IllegalUseOfScopeReplacer`` exception if it can figure out that this
773
happened. But it requires accessing a member more than once from the new
774
variable, so some bugs are not detected right away.
780
The null revision is the ancestor of all revisions. Its revno is 0, its
781
revision-id is ``null:``, and its tree is the empty tree. When referring
782
to the null revision, please use ``bzrlib.revision.NULL_REVISION``. Old
783
code sometimes uses ``None`` for the null revision, but this practice is
787
Object string representations
788
=============================
790
Python prints objects using their ``__repr__`` method when they are
791
written to logs, exception tracebacks, or the debugger. We want
792
objects to have useful representations to help in determining what went
795
If you add a new class you should generally add a ``__repr__`` method
796
unless there is an adequate method in a parent class. There should be a
799
Representations should typically look like Python constructor syntax, but
800
they don't need to include every value in the object and they don't need
801
to be able to actually execute. They're to be read by humans, not
802
machines. Don't hardcode the classname in the format, so that we get the
803
correct value if the method is inherited by a subclass. If you're
804
printing attributes of the object, including strings, you should normally
805
use ``%r`` syntax (to call their repr in turn).
807
Try to avoid the representation becoming more than one or two lines long.
808
(But balance this against including useful information, and simplicity of
811
Because repr methods are often called when something has already gone
812
wrong, they should be written somewhat more defensively than most code.
813
The object may be half-initialized or in some other way in an illegal
814
state. The repr method shouldn't raise an exception, or it may hide the
815
(probably more useful) underlying exception.
820
return '%s(%r)' % (self.__class__.__name__,
827
A bare ``except`` statement will catch all exceptions, including ones that
828
really should terminate the program such as ``MemoryError`` and
829
``KeyboardInterrupt``. They should rarely be used unless the exception is
830
later re-raised. Even then, think about whether catching just
831
``Exception`` (which excludes system errors in Python2.5 and later) would
838
All code should be exercised by the test suite. See :doc:`Guide to Testing
839
Bazaar <testing>` for detailed information about writing tests.
848
We have a commitment to 6 months API stability - any supported symbol in a
849
release of bzr MUST NOT be altered in any way that would result in
850
breaking existing code that uses it. That means that method names,
851
parameter ordering, parameter names, variable and attribute names etc must
852
not be changed without leaving a 'deprecated forwarder' behind. This even
853
applies to modules and classes.
855
If you wish to change the behaviour of a supported API in an incompatible
856
way, you need to change its name as well. For instance, if I add an optional keyword
857
parameter to branch.commit - that's fine. On the other hand, if I add a
858
keyword parameter to branch.commit which is a *required* transaction
859
object, I should rename the API - i.e. to 'branch.commit_transaction'.
861
When renaming such supported API's, be sure to leave a deprecated_method (or
862
_function or ...) behind which forwards to the new API. See the
863
bzrlib.symbol_versioning module for decorators that take care of the
864
details for you - such as updating the docstring, and issuing a warning
865
when the old API is used.
867
For unsupported API's, it does not hurt to follow this discipline, but it's
868
not required. Minimally though, please try to rename things so that
869
callers will at least get an AttributeError rather than weird results.
872
Deprecation decorators
873
----------------------
875
``bzrlib.symbol_versioning`` provides decorators that can be attached to
876
methods, functions, and other interfaces to indicate that they should no
877
longer be used. For example::
879
@deprecated_method(deprecated_in((0, 1, 4)))
881
return self._new_foo()
883
To deprecate a static method you must call ``deprecated_function``
884
(**not** method), after the staticmethod call::
887
@deprecated_function(deprecated_in((0, 1, 4)))
888
def create_repository(base, shared=False, format=None):
890
When you deprecate an API, you should not just delete its tests, because
891
then we might introduce bugs in them. If the API is still present at all,
892
it should still work. The basic approach is to use
893
``TestCase.applyDeprecated`` which in one step checks that the API gives
894
the expected deprecation message, and also returns the real result from
895
the method, so that tests can keep running.
897
Deprecation warnings will be suppressed for final releases, but not for
898
development versions or release candidates, or when running ``bzr
899
selftest``. This gives developers information about whether their code is
900
using deprecated functions, but avoids confusing users about things they
907
Processing Command Lines
908
------------------------
910
bzrlib has a standard framework for parsing command lines and calling
911
processing routines associated with various commands. See builtins.py
912
for numerous examples.
915
Standard Parameter Types
916
------------------------
918
There are some common requirements in the library: some parameters need to be
919
unicode safe, some need byte strings, and so on. At the moment we have
920
only codified one specific pattern: Parameters that need to be unicode
921
should be checked via ``bzrlib.osutils.safe_unicode``. This will coerce the
922
input into unicode in a consistent fashion, allowing trivial strings to be
923
used for programmer convenience, but not performing unpredictably in the
924
presence of different locales.
930
(The strategy described here is what we want to get to, but it's not
931
consistently followed in the code at the moment.)
933
bzrlib is intended to be a generically reusable library. It shouldn't
934
write messages to stdout or stderr, because some programs that use it
935
might want to display that information through a GUI or some other
938
We can distinguish two types of output from the library:
940
1. Structured data representing the progress or result of an
941
operation. For example, for a commit command this will be a list
942
of the modified files and the finally committed revision number
945
These should be exposed either through the return code or by calls
946
to a callback parameter.
948
A special case of this is progress indicators for long-lived
949
operations, where the caller should pass a ProgressBar object.
951
2. Unstructured log/debug messages, mostly for the benefit of the
952
developers or users trying to debug problems. This should always
953
be sent through ``bzrlib.trace`` and Python ``logging``, so that
954
it can be redirected by the client.
956
The distinction between the two is a bit subjective, but in general if
957
there is any chance that a library would want to see something as
958
structured data, we should make it so.
960
The policy about how output is presented in the text-mode client
961
should be only in the command-line tool.
964
Progress and Activity Indications
965
---------------------------------
967
bzrlib has a way for code to display to the user that stuff is happening
968
during a long operation. There are two particular types: *activity* which
969
means that IO is happening on a Transport, and *progress* which means that
970
higher-level application work is occurring. Both are drawn together by
973
Transport objects are responsible for calling `report_transport_activity`
976
Progress uses a model/view pattern: application code acts on a
977
`ProgressTask` object, which notifies the UI when it needs to be
978
displayed. Progress tasks form a stack. To create a new progress task on
979
top of the stack, call `bzrlib.ui.ui_factory.nested_progress_bar()`, then
980
call `update()` on the returned ProgressTask. It can be updated with just
981
a text description, with a numeric count, or with a numeric count and
982
expected total count. If an expected total count is provided the view
983
can show the progress moving along towards the expected total.
985
The user should call `finish` on the `ProgressTask` when the logical
986
operation has finished, so it can be removed from the stack.
988
Progress tasks have a complex relationship with generators: it's a very
989
good place to use them, but because python2.4 does not allow ``finally``
990
blocks in generators it's hard to clean them up properly. In this case
991
it's probably better to have the code calling the generator allocate a
992
progress task for its use and then call `finalize` when it's done, which
993
will close it if it was not already closed. The generator should also
994
finish the progress task when it exits, because it may otherwise be a long
995
time until the finally block runs.
1001
Bazaar has online help for various topics through ``bzr help COMMAND`` or
1002
equivalently ``bzr command -h``. We also have help on command options,
1003
and on other help topics. (See ``help_topics.py``.)
1005
As for python docstrings, the first paragraph should be a single-sentence
1006
synopsis of the command.
1008
The help for options should be one or more proper sentences, starting with
1009
a capital letter and finishing with a full stop (period).
1011
All help messages and documentation should have two spaces between
1015
Handling Errors and Exceptions
1016
==============================
1018
Commands should return non-zero when they encounter circumstances that
1019
the user should really pay attention to - which includes trivial shell
1022
Recommended values are:
1025
1. Conflicts in merge-like operations, or changes are present in
1026
diff-like operations.
1027
2. Unrepresentable diff changes (i.e. binary files that we cannot show
1029
3. An error or exception has occurred.
1030
4. An internal error occurred (one that shows a traceback.)
1032
Errors are handled through Python exceptions. Exceptions should be defined
1033
inside bzrlib.errors, so that we can see the whole tree at a glance.
1035
We broadly classify errors as either being either internal or not,
1036
depending on whether ``internal_error`` is set or not. If we think it's our
1037
fault, we show a backtrace, an invitation to report the bug, and possibly
1038
other details. This is the default for errors that aren't specifically
1039
recognized as being caused by a user error. Otherwise we show a briefer
1040
message, unless -Derror was given.
1042
Many errors originate as "environmental errors" which are raised by Python
1043
or builtin libraries -- for example IOError. These are treated as being
1044
our fault, unless they're caught in a particular tight scope where we know
1045
that they indicate a user errors. For example if the repository format
1046
is not found, the user probably gave the wrong path or URL. But if one of
1047
the files inside the repository is not found, then it's our fault --
1048
either there's a bug in bzr, or something complicated has gone wrong in
1049
the environment that means one internal file was deleted.
1051
Many errors are defined in ``bzrlib/errors.py`` but it's OK for new errors
1052
to be added near the place where they are used.
1054
Exceptions are formatted for the user by conversion to a string
1055
(eventually calling their ``__str__`` method.) As a convenience the
1056
``._fmt`` member can be used as a template which will be mapped to the
1057
error's instance dict.
1059
New exception classes should be defined when callers might want to catch
1060
that exception specifically, or when it needs a substantially different
1063
#. If it is something that a caller can recover from, a custom exception
1066
#. If it is a data consistency issue, using a builtin like
1067
``ValueError``/``TypeError`` is reasonable.
1069
#. If it is a programmer error (using an api incorrectly)
1070
``AssertionError`` is reasonable.
1072
#. Otherwise, use ``BzrError`` or ``InternalBzrError``.
1074
Exception strings should start with a capital letter and should not have a
1075
final fullstop. If long, they may contain newlines to break the text.
1081
Do not use the Python ``assert`` statement, either in tests or elsewhere.
1082
A source test checks that it is not used. It is ok to explicitly raise
1087
* It makes the behaviour vary depending on whether bzr is run with -O
1088
or not, therefore giving a chance for bugs that occur in one case or
1089
the other, several of which have already occurred: assertions with
1090
side effects, code which can't continue unless the assertion passes,
1091
cases where we should give the user a proper message rather than an
1093
* It's not that much shorter than an explicit if/raise.
1094
* It tends to lead to fuzzy thinking about whether the check is
1095
actually needed or not, and whether it's an internal error or not
1096
* It tends to cause look-before-you-leap patterns.
1097
* It's unsafe if the check is needed to protect the integrity of the
1099
* It tends to give poor messages since the developer can get by with
1100
no explanatory text at all.
1101
* We can't rely on people always running with -O in normal use, so we
1102
can't use it for tests that are actually expensive.
1103
* Expensive checks that help developers are better turned on from the
1104
test suite or a -D flag.
1105
* If used instead of ``self.assert*()`` in tests it makes them falsely pass with -O.
1111
When you change bzrlib, please update the relevant documentation for the
1112
change you made: Changes to commands should update their help, and
1113
possibly end user tutorials; changes to the core library should be
1114
reflected in API documentation.
1119
If you make a user-visible change, please add a note to the NEWS file.
1120
The description should be written to make sense to someone who's just
1121
a user of bzr, not a developer: new functions or classes shouldn't be
1122
mentioned, but new commands, changes in behaviour or fixed nontrivial
1123
bugs should be listed. See the existing entries for an idea of what
1126
Within each release, entries in the news file should have the most
1127
user-visible changes first. So the order should be approximately:
1129
* changes to existing behaviour - the highest priority because the
1130
user's existing knowledge is incorrect
1131
* new features - should be brought to their attention
1132
* bug fixes - may be of interest if the bug was affecting them, and
1133
should include the bug number if any
1134
* major documentation changes
1135
* changes to internal interfaces
1137
People who made significant contributions to each change are listed in
1138
parenthesis. This can include reporting bugs (particularly with good
1139
details or reproduction recipes), submitting patches, etc.
1144
The docstring of a command is used by ``bzr help`` to generate help output
1145
for the command. The list 'takes_options' attribute on a command is used by
1146
``bzr help`` to document the options for the command - the command
1147
docstring does not need to document them. Finally, the '_see_also'
1148
attribute on a command can be used to reference other related help topics.
1153
Functions, methods, classes and modules should have docstrings
1154
describing how they are used.
1156
The first line of the docstring should be a self-contained sentence.
1158
For the special case of Command classes, this acts as the user-visible
1159
documentation shown by the help command.
1161
The docstrings should be formatted as reStructuredText_ (like this
1162
document), suitable for processing using the epydoc_ tool into HTML
1165
.. _reStructuredText: http://docutils.sourceforge.net/rst.html
1166
.. _epydoc: http://epydoc.sourceforge.net/
1175
The copyright policy for bzr was recently made clear in this email (edited
1176
for grammatical correctness)::
1178
The attached patch cleans up the copyright and license statements in
1179
the bzr source. It also adds tests to help us remember to add them
1180
with the correct text.
1182
We had the problem that lots of our files were "Copyright Canonical
1183
Development Ltd" which is not a real company, and some other variations
1184
on this theme. Also, some files were missing the GPL statements.
1186
I want to be clear about the intent of this patch, since copyright can
1187
be a little controversial.
1189
1) The big motivation for this is not to shut out the community, but
1190
just to clean up all of the invalid copyright statements.
1192
2) It has been the general policy for bzr that we want a single
1193
copyright holder for all of the core code. This is following the model
1194
set by the FSF, which makes it easier to update the code to a new
1195
license in case problems are encountered. (For example, if we want to
1196
upgrade the project universally to GPL v3 it is much simpler if there is
1197
a single copyright holder). It also makes it clearer if copyright is
1198
ever debated, there is a single holder, which makes it easier to defend
1199
in court, etc. (I think the FSF position is that if you assign them
1200
copyright, they can defend it in court rather than you needing to, and
1201
I'm sure Canonical would do the same).
1202
As such, Canonical has requested copyright assignments from all of the
1205
3) If someone wants to add code and not attribute it to Canonical, there
1206
is a specific list of files that are excluded from this check. And the
1207
test failure indicates where that is, and how to update it.
1209
4) If anyone feels that I changed a copyright statement incorrectly, just
1210
let me know, and I'll be happy to correct it. Whenever you have large
1211
mechanical changes like this, it is possible to make some mistakes.
1213
Just to reiterate, this is a community project, and it is meant to stay
1214
that way. Core bzr code is copyright Canonical for legal reasons, and
1215
the tests are just there to help us maintain that.
1218
Miscellaneous Topics
1219
####################
1224
Bazaar has a few facilities to help debug problems by going into pdb_, the
1227
.. _pdb: http://docs.python.org/lib/debugger-commands.html
1229
If the ``BZR_PDB`` environment variable is set
1230
then bzr will go into pdb post-mortem mode when an unhandled exception
1233
If you send a SIGQUIT or SIGBREAK signal to bzr then it will drop into the
1234
debugger immediately. SIGQUIT can be generated by pressing Ctrl-\\ on
1235
Unix. SIGBREAK is generated with Ctrl-Pause on Windows (some laptops have
1236
this as Fn-Pause). You can continue execution by typing ``c``. This can
1237
be disabled if necessary by setting the environment variable
1238
``BZR_SIGQUIT_PDB=0``.
1244
Bazaar accepts some global options starting with ``-D`` such as
1245
``-Dhpss``. These set a value in `bzrlib.debug.debug_flags`, and
1246
typically cause more information to be written to the trace file. Most
1247
`mutter` calls should be guarded by a check of those flags so that we
1248
don't write out too much information if it's not needed.
1250
Debug flags may have effects other than just emitting trace messages.
1252
Run ``bzr help global-options`` to see them all.
1254
These flags may also be set as a comma-separated list in the
1255
``debug_flags`` option in e.g. ``~/.bazaar/bazaar.conf``. (Note that it
1256
must be in this global file, not in the branch or location configuration,
1257
because it's currently only loaded at startup time.) For instance you may
1258
want to always record hpss traces and to see full error tracebacks::
1260
debug_flags = hpss, error
1267
Integer identifier for a revision on the main line of a branch.
1268
Revision 0 is always the null revision; others are 1-based
1269
indexes into the branch's revision history.
1272
Unicode and Encoding Support
1273
============================
1275
This section discusses various techniques that Bazaar uses to handle
1276
characters that are outside the ASCII set.
1281
When a ``Command`` object is created, it is given a member variable
1282
accessible by ``self.outf``. This is a file-like object, which is bound to
1283
``sys.stdout``, and should be used to write information to the screen,
1284
rather than directly writing to ``sys.stdout`` or calling ``print``.
1285
This file has the ability to translate Unicode objects into the correct
1286
representation, based on the console encoding. Also, the class attribute
1287
``encoding_type`` will effect how unprintable characters will be
1288
handled. This parameter can take one of 3 values:
1291
Unprintable characters will be represented with a suitable replacement
1292
marker (typically '?'), and no exception will be raised. This is for
1293
any command which generates text for the user to review, rather than
1294
for automated processing.
1295
For example: ``bzr log`` should not fail if one of the entries has text
1296
that cannot be displayed.
1299
Attempting to print an unprintable character will cause a UnicodeError.
1300
This is for commands that are intended more as scripting support, rather
1301
than plain user review.
1302
For example: ``bzr ls`` is designed to be used with shell scripting. One
1303
use would be ``bzr ls --null --unknowns | xargs -0 rm``. If ``bzr``
1304
printed a filename with a '?', the wrong file could be deleted. (At the
1305
very least, the correct file would not be deleted). An error is used to
1306
indicate that the requested action could not be performed.
1309
Do not attempt to automatically convert Unicode strings. This is used
1310
for commands that must handle conversion themselves.
1311
For example: ``bzr diff`` needs to translate Unicode paths, but should
1312
not change the exact text of the contents of the files.
1315
``bzrlib.urlutils.unescape_for_display``
1316
----------------------------------------
1318
Because Transports work in URLs (as defined earlier), printing the raw URL
1319
to the user is usually less than optimal. Characters outside the standard
1320
set are printed as escapes, rather than the real character, and local
1321
paths would be printed as ``file://`` urls. The function
1322
``unescape_for_display`` attempts to unescape a URL, such that anything
1323
that cannot be printed in the current encoding stays an escaped URL, but
1324
valid characters are generated where possible.
1330
The ``bzrlib.osutils`` module has many useful helper functions, including
1331
some more portable variants of functions in the standard library.
1333
In particular, don't use ``shutil.rmtree`` unless it's acceptable for it
1334
to fail on Windows if some files are readonly or still open elsewhere.
1335
Use ``bzrlib.osutils.rmtree`` instead.
1341
We write some extensions in C using pyrex. We design these to work in
1344
* User with no C compiler
1345
* User with C compiler
1348
The recommended way to install bzr is to have a C compiler so that the
1349
extensions can be built, but if no C compiler is present, the pure python
1350
versions we supply will work, though more slowly.
1352
For developers we recommend that pyrex be installed, so that the C
1353
extensions can be changed if needed.
1355
For the C extensions, the extension module should always match the
1356
original python one in all respects (modulo speed). This should be
1357
maintained over time.
1359
To create an extension, add rules to setup.py for building it with pyrex,
1360
and with distutils. Now start with an empty .pyx file. At the top add
1361
"include 'yourmodule.py'". This will import the contents of foo.py into this
1362
file at build time - remember that only one module will be loaded at
1363
runtime. Now you can subclass classes, or replace functions, and only your
1364
changes need to be present in the .pyx file.
1366
Note that pyrex does not support all 2.4 programming idioms, so some
1367
syntax changes may be required. I.e.
1369
- 'from foo import (bar, gam)' needs to change to not use the brackets.
1370
- 'import foo.bar as bar' needs to be 'import foo.bar; bar = foo.bar'
1372
If the changes are too dramatic, consider
1373
maintaining the python code twice - once in the .pyx, and once in the .py,
1374
and no longer including the .py file.
1377
Making Installers for OS Windows
1378
================================
1379
To build a win32 installer, see the instructions on the wiki page:
1380
http://bazaar-vcs.org/BzrWin32Installer
1383
Core Developer Tasks
1384
####################
1389
What is a Core Developer?
1390
-------------------------
1392
While everyone in the Bazaar community is welcome and encouraged to
1393
propose and submit changes, a smaller team is reponsible for pulling those
1394
changes together into a cohesive whole. In addition to the general developer
1395
stuff covered above, "core" developers have responsibility for:
1398
* reviewing blueprints
1400
* managing releases (see :doc:`Releasing Bazaar <releasing>`)
1403
Removing barriers to community participation is a key reason for adopting
1404
distributed VCS technology. While DVCS removes many technical barriers,
1405
a small number of social barriers are often necessary instead.
1406
By documenting how the above things are done, we hope to
1407
encourage more people to participate in these activities, keeping the
1408
differences between core and non-core contributors to a minimum.
1411
Communicating and Coordinating
1412
------------------------------
1414
While it has many advantages, one of the challenges of distributed
1415
development is keeping everyone else aware of what you're working on.
1416
There are numerous ways to do this:
1418
#. Assign bugs to yourself in Launchpad
1419
#. Mention it on the mailing list
1420
#. Mention it on IRC
1422
As well as the email notifcations that occur when merge requests are sent
1423
and reviewed, you can keep others informed of where you're spending your
1424
energy by emailing the **bazaar-commits** list implicitly. To do this,
1425
install and configure the Email plugin. One way to do this is add these
1426
configuration settings to your central configuration file (e.g.
1427
``~/.bazaar/bazaar.conf`` on Linux)::
1430
email = Joe Smith <joe.smith@internode.on.net>
1431
smtp_server = mail.internode.on.net:25
1433
Then add these lines for the relevant branches in ``locations.conf``::
1435
post_commit_to = bazaar-commits@lists.canonical.com
1436
post_commit_mailer = smtplib
1438
While attending a sprint, RobertCollins' Dbus plugin is useful for the
1439
same reason. See the documentation within the plugin for information on
1440
how to set it up and configure it.
1449
Of the many workflows supported by Bazaar, the one adopted for Bazaar
1450
development itself is known as "Decentralized with automatic gatekeeper".
1451
To repeat the explanation of this given on
1452
http://bazaar-vcs.org/Workflows:
1455
In this workflow, each developer has their own branch or
1456
branches, plus read-only access to the mainline. A software gatekeeper
1457
(e.g. PQM) has commit rights to the main branch. When a developer wants
1458
their work merged, they request the gatekeeper to merge it. The gatekeeper
1459
does a merge, a compile, and runs the test suite. If the code passes, it
1460
is merged into the mainline.
1462
In a nutshell, here's the overall submission process:
1464
#. get your work ready (including review except for trivial changes)
1465
#. push to a public location
1466
#. ask PQM to merge from that location
1469
At present, PQM always takes the changes to merge from a branch
1470
at a URL that can be read by it. For Bazaar, that means a public,
1471
typically http, URL.
1473
As a result, the following things are needed to use PQM for submissions:
1475
#. A publicly available web server
1476
#. Your OpenPGP key registered with PQM (contact RobertCollins for this)
1477
#. The PQM plugin installed and configured (not strictly required but
1478
highly recommended).
1481
Selecting a Public Branch Location
1482
----------------------------------
1484
If you don't have your own web server running, branches can always be
1485
pushed to Launchpad. Here's the process for doing that:
1487
Depending on your location throughout the world and the size of your
1488
repository though, it is often quicker to use an alternative public
1489
location to Launchpad, particularly if you can set up your own repo and
1490
push into that. By using an existing repo, push only needs to send the
1491
changes, instead of the complete repository every time. Note that it is
1492
easy to register branches in other locations with Launchpad so no benefits
1493
are lost by going this way.
1496
For Canonical staff, http://people.ubuntu.com/~<user>/ is one
1497
suggestion for public http branches. Contact your manager for information
1498
on accessing this system if required.
1500
It should also be noted that best practice in this area is subject to
1501
change as things evolve. For example, once the Bazaar smart server on
1502
Launchpad supports server-side branching, the performance situation will
1503
be very different to what it is now (Jun 2007).
1506
Configuring the PQM Plug-In
1507
---------------------------
1509
While not strictly required, the PQM plugin automates a few things and
1510
reduces the chance of error. Before looking at the plugin, it helps to
1511
understand a little more how PQM operates. Basically, PQM requires an
1512
email indicating what you want it to do. The email typically looks like
1515
star-merge source-branch target-branch
1519
star-merge http://bzr.arbash-meinel.com/branches/bzr/jam-integration http://bazaar-vcs.org/bzr/bzr.dev
1521
Note that the command needs to be on one line. The subject of the email
1522
will be used for the commit message. The email also needs to be ``gpg``
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signed with a key that PQM accepts.
1525
The advantages of using the PQM plugin are:
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#. You can use the config policies to make it easy to set up public
1528
branches, so you don't have to ever type the full paths you want to merge
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#. It checks to make sure the public branch last revision matches the
1532
local last revision so you are submitting what you think you are.
1534
#. It uses the same public_branch and smtp sending settings as bzr-email,
1535
so if you have one set up, you have the other mostly set up.
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#. Thunderbird refuses to not wrap lines, and request lines are usually
1538
pretty long (you have 2 long URLs in there).
1540
Here are sample configuration settings for the PQM plugin. Here are the
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lines in bazaar.conf::
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email = Joe Smith <joe.smith@internode.on.net>
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smtp_server=mail.internode.on.net:25
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And here are the lines in ``locations.conf`` (or ``branch.conf`` for
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dirstate-tags branches)::
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[/home/joe/bzr/my-integration]
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push_location = sftp://joe-smith@bazaar.launchpad.net/%7Ejoe-smith/bzr/my-integration/
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push_location:policy = norecurse
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public_branch = http://bazaar.launchpad.net/~joe-smith/bzr/my-integration/
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public_branch:policy = appendpath
1555
pqm_email = Bazaar PQM <pqm@bazaar-vcs.org>
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pqm_branch = http://bazaar-vcs.org/bzr/bzr.dev
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Note that the push settings will be added by the first ``push`` on
1559
a branch. Indeed the preferred way to generate the lines above is to use
1560
``push`` with an argument, then copy-and-paste the other lines into
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Here is one possible recipe once the above environment is set up:
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#. pull bzr.dev => my-integration
1570
#. merge patch => my-integration
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#. fix up any final merge conflicts (NEWS being the big killer here).
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The ``push`` step is not required if ``my-integration`` is a checkout of
1580
Because of defaults, you can type a single message into commit and
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pqm-commit will reuse that.
1584
Tracking Change Acceptance
1585
--------------------------
1587
The web interface to PQM is https://pqm.bazaar-vcs.org/. After submitting
1588
a change, you can visit this URL to confirm it was received and placed in
1591
When PQM completes processing a change, an email is sent to you with the
1595
Reviewing Blueprints
1596
====================
1598
Blueprint Tracking Using Launchpad
1599
----------------------------------
1601
New features typically require a fair amount of discussion, design and
1602
debate. For Bazaar, that information is often captured in a so-called
1603
"blueprint" on our Wiki. Overall tracking of blueprints and their status
1604
is done using Launchpad's relevant tracker,
1605
https://blueprints.launchpad.net/bzr/. Once a blueprint for ready for
1606
review, please announce it on the mailing list.
1608
Alternatively, send an email beginning with [RFC] with the proposal to the
1609
list. In some cases, you may wish to attach proposed code or a proposed
1610
developer document if that best communicates the idea. Debate can then
1611
proceed using the normal merge review processes.
1614
Recording Blueprint Review Feedback
1615
-----------------------------------
1617
Unlike its Bug Tracker, Launchpad's Blueprint Tracker doesn't currently
1618
(Jun 2007) support a chronological list of comment responses. Review
1619
feedback can either be recorded on the Wiki hosting the blueprints or by
1620
using Launchpad's whiteboard feature.
1627
Using Releases and Milestones in Launchpad
1628
------------------------------------------
1630
TODO ... (Exact policies still under discussion)
1636
Keeping on top of bugs reported is an important part of ongoing release
1637
planning. Everyone in the community is welcome and encouraged to raise
1638
bugs, confirm bugs raised by others, and nominate a priority. Practically
1639
though, a good percentage of bug triage is often done by the core
1640
developers, partially because of their depth of product knowledge.
1642
With respect to bug triage, core developers are encouraged to play an
1643
active role with particular attention to the following tasks:
1645
* keeping the number of unconfirmed bugs low
1646
* ensuring the priorities are generally right (everything as critical - or
1647
medium - is meaningless)
1648
* looking out for regressions and turning those around sooner rather than later.
1651
As well as prioritizing bugs and nominating them against a
1652
target milestone, Launchpad lets core developers offer to mentor others in
1657
vim: ft=rst tw=74 ai
added
removed
doc/developers/HACKING.txt
