[Python-Dev] Mercurial migration: progress report (PEP 385)

["Martin v. Löwis"]

> We could add another value in the tuple that specifies the VCS:
> ('CPython', 'branches/release25-maint', '61464', 'svn'). I agree that
> VCSs are not universally the same, but the concept of a revision is
> universal.

Actually, I think that's not the case. For bzr, the usual way of
identifying a revision is by revision number, which, however, is not
unique within a project, as each branch will use contiguous integers
for numbers. There are also unique identifications - so a bzr revision
has actually two numbers.

More general, in a DVCS, it is not possible to access the revision being
referred to by such a tuple. For sys.subversion, if [0]=='CPython', then
you could go to svn.python.org. For a DVCS, the revision being
identified may not be publically available, or may not live on a host
that you can infer from your proposed sys.revision.

For cloned branches, I wonder how sys.revision[1] would be computed.

Regards,
Martin