fix and test --fixtures location information

_pytest/python.py

@@ -761,7 +761,7 @@ def _showfixtures_main(config, session):
         if verbose <= 0 and argname[0] == "_":
             continue
         if verbose > 0:
-            funcargspec = "%s -- %s" %(argname, loc,)
+            funcargspec = "%s -- %s" %(argname, bestrel,)
         else:
             funcargspec = argname
         tw.line(funcargspec, green=True)

testing/test_python.py

@@ -1590,7 +1590,7 @@ class TestShowFixtures:
     def test_show_fixtures_verbose(self, testdir):
         result = testdir.runpytest("--fixtures", "-v")
         result.stdout.fnmatch_lines([
-                "*tmpdir*",
+                "*tmpdir*--*tmpdir.py*",
                 "*temporary directory*",
             ]
         )