Description of problem:

mktemp uses the TMPDIR environment variable. The brp-java-repack-jars script
resets TMPDIR to arbitrary values that don't necessarily exist, and then tries
to use mktemp. Failures ensue.

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

redhat-rpm-config-8.0.45-14.fc7

How reproducible:

intrinsic

Steps to Reproduce:
1. try to build, for example, a jpackage.org nosrc rpm
2. watch it not work.
3. there is no step three.
  
Actual results:

it fails with an error message about a temporary directory not existing.

Expected results:

it shouldn't be looking there anyway

Additional info:

replace all instances of TMPDIR in this script with something like JTMPDIR and
the problem is solved