unit-test: add debug in dependency determination

We are running into a periodic error where 'build_dep_tree' fails
because it is unable to probe the build system used by a dependency.
Add some debug statements so we are able to determine which dependency
this is.

Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
Change-Id: I571d62f191adcab42b4e1814dc6435b1401f3bb8
1 file changed