mock improvements

[Mike Bonnet]

On Tue, 2007-09-25 at 14:11 -0500, Michael E Brown wrote:
> So here is the list of things that have been requested lately and I'll
> be working on a few of these over the next few weeks. If anybody has any
> input, I'd take it. As I start on each, I'll most likely email the
> mailing list with the outline of what I'm doing.
> 
> If anybody has existing patches for these (against current mock git),
> all the better... :)
> 
> 1) more reliable mount/umount
>   several people have pointed out instances where mock exits leaving
>   mounts behind (specifically /dev), and the next invokation of mock
>   ends up 'rm -rf' the host machine's /dev. Bad....
> 
> 2) caching yum downloads
>   several people have commented that the autocache stuff is great for
>   speeding up builds, others say that it can sometimes be bad for
>   reproducability, and that simply saving the yum cache dir would be
>   better.
> 
> 3) ccache integration
>   This is a new one that I havent seen before, but should significantly
>   speed up builds for people who often do
>   rebuild-the-entire-distribution-type things. I'm told by some that
>   this is bad for reproducability, but good for speeding up builds when
>   you are just sanity checking or when that small reproducability hit
>   doesnt matter. I've also seen lots of empirical data that ccache
>   should not cause any problems. This will be have to be specifically
>   enabled through a commandline or config file option, so those who care
>   can turn it on/off.
> 
> 4) distcc integration
>   Pretty much the same case as ccache. Has more things that need thought
>   than the ccache case, above, though.

A method for cleaning up stale/orphaned processes that get created
during a build was proposed a while ago:

https://bugzilla.redhat.com/show_bug.cgi?id=221351

I'll leave it to you as to whether or not this is the correct
implementation, but I certainly think it's a good idea.  I see rogue
processes consuming resources on the build machines all the time.  The
process-cleanup code should probably be run before mock exits, whether
the build completed successfully or not.