mock improvements

[Michael E Brown]

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.

--
Michael