Re: [Qemu-devel] Switch to GIT. Why?

[M. Warner Losh]

In message: <address@hidden>
            address@hidden (Lennart Sorensen) writes:
: On Sun, Apr 26, 2009 at 01:13:20AM -0600, M. Warner Losh wrote:
: > At the expense, at least with hg and git, that you can't do subtree
: > checkouts.  You also lose the strict numbering that svn was giving us,
: > since both git and hg compute a hash of the tree and use that as a
: > revision number.  Usually this isn't a big deal, but something to be
: > aware of if you used to checkout sub-trees to do bug bisection...
: 
: But of course that is part of why svn can't merge from one tree to
: another without loosing the history and git can (and I suspect Hg can
: as well).  So the strict numbering while it seems very useful, is actually
: a problem in many cases.

Yes.  And that's why you can only check out entire trees, and never
subtrees, with git and hg, but you can with svn.  git and hg force a
small view of the system to be its own repo.  So something the size of
X11 or FreeBSD could never use git or hg without breaking the
integrated tree model.  FreeBSD used svn to not break it because we
like the development model we have (and think Linus' talk at google
was very arrogant to suggest it was broken), while the X11 folks broke
their tree up into lots of modules, and got out of the making sure it
all worked together business (which makes integrating X11 into systems
harder now, alas).

For qemu, none of these issues are likely to be an issue, but it is
something to keep in mind...

Warner