[Buildbot-devel] Recovering from having wrong git installed on cygwin

[Dan Kegel]

The FAQ notes that there are problems on cygwin if you have the wrong
git installed.

For small projects, if you accidentally have 'native' git installed,
running buildslaves on cygwin seems fine.

For larger ones... mine failied to check out a source tree with git.
On the master log, I saw things like

2012-11-13 16:48:16-0800 [-] Starting git command : git clone --branch
iz git.oblong.com:~cp/pub/yovo.git .
2012-11-13 16:48:16-0800 [-] <RemoteShellCommand '['git', 'clone',
'--branch', u'iz', 'git.oblong.com:~cp/pub/yovo.git', '.']'>:
RemoteCommand.run [3]
2012-11-13 16:48:16-0800 [-] command '['git', 'clone', '--branch',
u'iz', 'git.oblong.com:~cp/pub/yovo.git', '.']' in dir 'source'

and then it just hung for a long time.

Worse, when I press 'cancel build', the build... keeps hanging.  It
doesn't go away.
The status page for the build gets another 'interrupt' entry; they
pile up, so it looks like this:

git updating ( running )
stdio
interrupt
interrupt
interrupt
interrupt
interrupt

Recovering from this mess was hard.  First I had to figure out that
the wrong git was being
invoked -- oddly, cygwin's PATH didn't have /bin first.

I had to uninstall the wrong git, then blow away both master and slave totally.

Yup, having the wrong git on the slave somehow corrupted the state on
the master.

Or maybe I was just having a bad day.

Anyway, posting this in case it helps someone else later.