Issue 24 in f2py: Switching from SVN to Mercurial

[f2...@googlecode.com]

Status: Accepted
Owner: pearu.peterson
Labels: Type-Enhancement Priority-Medium

New issue 24 by pearu.peterson: Switching from SVN to Mercurial
http://code.google.com/p/f2py/issues/detail?id=24

Kurt (kwmsmith) has suggested to switch f2py svn repository to mercurial
repository. Googlecode provides instructions for that

http://code.google.com/p/support/wiki/ConvertingSvnToHg

Now I have the following questions:

1) Does anyone have any objections for the switch? It would be nice if
all f2py commiters could give a short answer whether they agree or disagree
with the switch.

2) Do we want to keep full log history?

[f2...@googlecode.com]

Comment #1 on issue 24 by pearu.peterson: Switching from SVN to Mercurial
http://code.google.com/p/f2py/issues/detail?id=24

Now I recalled that f2py setup.py scripts create __svn_version__.py
file using the svnrevision program. Is there any equivalent hg command
that would produce a revision number that would be usable in version
strings?

[f2...@googlecode.com]

Comment #2 on issue 24 by omar.aw...@gmail.com: Switching from SVN to
Mercurial
http://code.google.com/p/f2py/issues/detail?id=24

Is there any reason to switch to mercurial? I mean, I wouldn't mind
switching, but if there is no real reason to do the switch, then why the
effort? Would we or the project benefit from using mercurial instead?

[f2...@googlecode.com]

Updates:
Cc: kwmsmith

Comment #3 on issue 24 by pearu.peterson: Switching from SVN to Mercurial
http://code.google.com/p/f2py/issues/detail?id=24

CC'ing to Kurt.

This is a good question. Google gives many documents that compare
mercurial and subversion (and other) systems. Personally I am satisfied
with using subversion for the f2py project. Currently its development
is not too rapid and I don't see reasons for creating branches
(in which mercurial is much better than subversion).

On the other hand, I can understand and I would take advantage of mercurial
features such as using local repository for rapid development and then the
main repository when development has stabilized.

Also, since Kurt has created a personal fparser hg repository for working
with experimental features (such as using logger for outputting fparser
messages), then
I don't mind switching to mercurial when it helps the project to evolve
further with the tools that the project developers are more used to or
think that these tools would ease the development cycle.

Btw, switching to mercurial is not a big effort when ignoring history (see
googlecode instructions). Moreover, the current svn repository will still
be available after the switch, that is, the commit history is not really
lost.
So, I think that the effort to switch is minimal and the real question is
whether
using mercurial will help the development of the project, will it ease the
life
of developers or will it make it harder for someone.

[f2...@googlecode.com]

Comment #4 on issue 24 by kwmsmith: Switching from SVN to Mercurial
http://code.google.com/p/f2py/issues/detail?id=24

Kyle Mandli and I worked on fparser a bit during the Scipy 2010
conference. We put a mercurial repository of fparser up on bitbucket, and
it makes it *much* easier to try out experimental branches, etc. like Pearu
mentions. I'll be pushing the improvements to svn soon. The Cython project
uses mercurial, and doing merges between branches and other repos is a nice
experience, something I couldn't imagine even trying with svn. If the
switch to mercurial doesn't take too much effort then I'm all for it,
although that's easy for me to say :-) Since there isn't much history in
fparser on googlecode I certainly don't mind restarting the repo at the svn
HEAD, especially since the original history is still there.

It's possible to work with a remote svn repo with mercurial locally, but it
is somewhat kludgy, and I think there are definite benefits to using a DVCS
for everyone involved. It takes a bit getting used to, though.

I'll take a look at the __svn_version__.py script and figure out the
mercurial equivalent.

And to be clear: If it isn't too hard, keeping log history would be great,
but it's up to Pearu or whoever does the conversion. There isn't that much
history in the googlecode svn repo.

[f2...@googlecode.com]

Comment #5 on issue 24 by kwmsmith: Switching from SVN to Mercurial
http://code.google.com/p/f2py/issues/detail?id=24

So the 'equivalent' of svnversion is:

$ hg identify --id
f4596fa7a3b9

Which gives the global revision id for the working copy (the currently
checked-out revision). There are other options to fine-tune what is
output, see:

$ hg help identify

If there are uncommitted changes, it looks like:

$ hg identify --id
f4596fa7a3b9+

(a '+' is appended...)

[f2...@googlecode.com]

Comment #6 on issue 24 by omar.aw...@gmail.com: Switching from SVN to
Mercurial
http://code.google.com/p/f2py/issues/detail?id=24

OK, sounds good! I've never used mercurial before, but as it seems to help
with development and give the developers more freedom trying out stuff in a
local repository (which is actually something I missed in svn when playing
with the f2py code), I'm in! Let me know if I can help with migrating to
the new repo.

[f2...@googlecode.com]

Comment #7 on issue 24 by pearu.peterson: Switching from SVN to Mercurial
http://code.google.com/p/f2py/issues/detail?id=24

Ok, I shall prepare the repository for the switch (introducing
__hg_version__.py)
and do the conversion hopefully within couple of hours. Kurt, if you cannot
making
the push sooner then it's ok, the improvements can be pushed also to a new
repository.

[f2...@googlecode.com]

Comment #8 on issue 24 by pearu.peterson: Switching from SVN to Mercurial
http://code.google.com/p/f2py/issues/detail?id=24

The switch to Mercurial with complete history is now done (it was very
easy).

Creating source distribution of f2py requires numpy revision 8527 or newer
that has now __hg_version__.py file generation support. For all other
tasks you may still use your favorite numpy version.

Anyone can create a clone of f2py in

http://code.google.com/p/f2py/source/checkout

For suggested work flow, read also

http://code.google.com/p/support/wiki/MercurialFAQ#Why_should_I_create_a_server-side_clone?

[f2...@googlecode.com]

Comment #9 on issue 24 by omar.aw...@gmail.com: Switching from SVN to
Mercurial
http://code.google.com/p/f2py/issues/detail?id=24

Thanks, Pearu!

[f2...@googlecode.com]

Updates:
Status: Done

Comment #10 on issue 24 by pearu.peterson: Switching from SVN to Mercurial
http://code.google.com/p/f2py/issues/detail?id=24

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