tmperamental is a library that intercepts filesystem writes, and causes loud failures when writes are attempted on /tmp/*.
The idea here is by setting TMPDIR and friends, you are able to use libtmperamental to catch programs in the act of not respecting such env-vars.
TMPDIR=~/.tmp LD_PRELOAD=/usr/lib/libtmperamental.so app arguments
In the event the app causes problems, you should see some stderr and a nonzero exit status.
This library is not to be linked against, just preloaded.