test(fix): keep SourceIncludeOmitTest's from clobbering each other

Because they cd'd into a folder in the shared source tree, their data
files would collide, leading to flaky tests.

Also, add a check that the tests collected some data, and add sys.path
to the debug=trace output.

1 files changed, 3 insertions, 0 deletions

diff --git a/coverage/inorout.py b/coverage/inorout.py
index 69084b26..2ab7d493 100644
--- a/coverage/inorout.py
+++ b/coverage/inorout.py
@@ -243,6 +243,9 @@ class InOrOut:
             if self.debug:
                 self.debug.write(msg)
 
+        # Generally useful information
+        debug("sys.path:" + "".join(f"\n    {p}" for p in sys.path))
+
         # Create the matchers we need for should_trace
         if self.source or self.source_pkgs:
             against = []