Allow CVS checkout/export of multiple modules

[satyagraha]

The standard CVS checkout/export syntax allows not just one, but multiple, modules to be checked out/exported, see  http://www.cs.utah.edu/dept/old/texinfo/cvs/cvs_18.html#SEC73 . I had a clear requirement to do just this in my buildbot, and doing multiple separate source.CVS() calls for each module did not seem to work well due to purging of directories. Therefore, I propose that the cvsmodule parameter of source.CVS() be generalised to accept a list of module path strings in addition to just a single string as at present; all the specified modules would be checked out/exported at once.

I have implemented this functionality on my buildbot system in just a couple of lines of code, and it works perfectly. Note that in this scenario one would normally expect to use the additional (currently undocumented) parameter checkout_options=['-N'] to ensure that the full directory tree was retained for each module and the multiple checkouts/exports did not end up on top of each other.

If this proposal is acceptable, I am happy to push up the change and updated documentation.

[satyagraha]

Fix now added at:  http://github.com/satyagraha/buildbot/commit/7cea218545698446017fbe15a9af55840cb0af7a

[marcusl]

Neat!

Howewer, please write the problem or describe fix in commit message, then end with "(fixes #xxx)" instead. (see #673 as an exacmple)

This makes it much easier to browse the commit history and find commits related to a certain part without having to look up ticket numbers in Trac. (and if we shift bug system, it's not totally hopeless)

[dustin]

satya - Marcus said it all. The code looks fine. Drop by #buildbot if you need help with the github stuff. You may also want to set your git author information to something other than "unknown" so you get credit :)

[satyagraha]

Thanks. Just for completeness, it's worth mentioning that I recently found a fairly old posting which points out that PBChangeSource can't handle changes in multiple modules:  http://osdir.com/ml/python.buildbot.devel/2005-08/msg00019.html (see point labelled 3.).

Presumably it's possible to have two (or more) separate CVS change detectors, one for each module, which all trigger the same build? If not, you'd have to use the highest common file prefix, with a risk of false triggering I guess. For my application, nightly builds were fine so I haven't investigated that question.

[dustin]

Yeah, support for that sort of thing is sparse in buildbot, sadly. Once the schedulerdb work hits the trunk, I think we'll have a nice starting-point for progress on that front.

[dustin]

Please take a look at the new project and repository support that was just committed. Changes and SourceStamps? can indicate their repository and project, and Schedulers can filter on it. What remains is to adjust the source steps to do things like what you've described here.

[dustin]

Bill, were you going to get this merged? What's the status?

[tom.prince]

This is probably best handled via the new multi-codebase support.