Description of problem:

A lockfile normally stops two yum instances running in parallel.
debuginfo-install doesn't grab this lock

Version-Release number of selected component (if applicable):

yum-utils-1.1.11-1.fc8
yum-3.2.8-2.fc8

How reproducible: Always


Steps to Reproduce:
1. Run yum install <some large package>
2. While that runs, run debuginfo-install <some large package>
  
Actual results:

Both run simultaneously. When the second one goes to install, it pauses with:

warning: waiting for transaction lock on /var/lib/rpm/__db.000

Expected results: Second command pauses with:

Existing lock /var/run/yum.pid: another copy is running as pid 6402.
Another app is currently holding the yum lock; waiting for it to exit...

Additional info: Both runs were downloading the metadata at the same time,
although for different repos. Not sure if theres an extra lock stopping those
two downloads from clobbering each other