Determining why a test is unsupported

I have a test that fails during cmake (lit) testing but when I run it
with llvm-lit in an interactive shell, lit reports the test is
unsupported. The test does not have UNSUPPORTED or REQUIRES clauses but
there is a lit.local.cfg that spells out when the test is unsupported.
However, I see nothing in there that would cause the test to be
unsupported on the host.

Is there a relatively simple way to have lit spit out why it thinks a
test is unsupported?

                          -David