Occasionally in testing logs, we'll see something like this:
[13:59:04] Invoking operation [syntax]...
[13:59:04] Checked [0 of 3] relevant file(s) for syntax.
Digging a little deeper, it appears that this is due to the module directory prefix being prepended to the filenames within the syntax_files() calls. The first call goes to the syntax_files() function inside of pifr_drupal.client.inc, which in turn calls parent::syntax_files() to execute the function inside of client.inc - and both versions prefix the module directory. As a result, the files can't be found, and don't get syntax checked.
I suspect that this could be happinging for any patches to contrib projects which contain tests (though I haven't dug through any logs or are run through sample tests to confirm this suspicion).
Where this might get interesting is that syntax_files() is also called from pifr_simpletest.client.inc, inside the test_list() function ... if the same issue is happening here, this MIGHT explain why a full suite of tests are being executed for contrib projects! *fingers crossed*