tox: enable python 3.5 & 3.9 testing

We still support Python 3.5, so make sure it keeps working.

Change-Id: I150158a656b26de6d733316a68a2cbb8b5b99716
Reviewed-on: https://gerrit-review.googlesource.com/c/git-repo/+/299625
Reviewed-by: Michael Mortensen <mmortensen@google.com>
Tested-by: Mike Frysinger <vapier@google.com>

1 files changed, 2 insertions, 2 deletions

diff --git a/run_tests b/run_tests
index 07cd98db..6c6f8594 100755
--- a/run_tests
+++ b/run_tests
@@ -34,8 +34,8 @@ def find_pytest():
   if ret:
     return ret
 
-  print(f'{__file__}: unable to find pytest.', file=sys.stderr)
-  print(f'{__file__}: Try installing: sudo apt-get install python-pytest',
+  print('%s: unable to find pytest.' % (__file__,), file=sys.stderr)
+  print('%s: Try installing: sudo apt-get install python-pytest' % (__file__,),
         file=sys.stderr)