Do not call signal.strsignal() when not available (py<3.8)

Signed-off-by: Michał Górny <mgorny@gentoo.org>

2 files changed, 15 insertions, 4 deletions

diff --git a/gemato/cli.py b/gemato/cli.py
index 22b19f7..8b28b5e 100644
--- a/gemato/cli.py
+++ b/gemato/cli.py
@@ -589,8 +589,12 @@ class GnuPGWrapCommand(VerifyingOpenPGPMixin, GematoCommand):
         p = subprocess.Popen(self.argv)
         ret = p.wait()
         if ret < 0:
-            logging.error(f'Child process terminated due to signal: '
-                          f'{signal.strsignal(-ret)}')
+            if hasattr(signal, 'strsignal'):
+                sig = signal.strsignal(-ret)
+            else:
+                sig = -ret
+            logging.error(
+                f'Child process terminated due to signal: {sig}')
         return ret
 
 
diff --git a/tests/test_openpgp.py b/tests/test_openpgp.py
index 69f0aad..3125d3a 100644
--- a/tests/test_openpgp.py
+++ b/tests/test_openpgp.py
@@ -845,6 +845,13 @@ def test_get_wkd_url(email, expected):
     assert OpenPGPEnvironment.get_wkd_url(email) == expected
 
 
+def signal_desc(sig):
+    if hasattr(signal, 'strsignal'):
+        return signal.strsignal(sig)
+    else:
+        return sig
+
+
 @pytest.mark.parametrize(
     'command,expected,match',
     [('true', 0, None),
@@ -853,10 +860,10 @@ def test_get_wkd_url(email, expected):
      ('gpg --verify {tmp_path}/Manifest.subkey', 2, None),
      ('sh -c "kill $$"', -signal.SIGTERM,
       f'Child process terminated due to signal: '
-      f'{signal.strsignal(signal.SIGTERM)}'),
+      f'{signal_desc(signal.SIGTERM)}'),
      ('sh -c "kill -USR1 $$"', -signal.SIGUSR1,
       f'Child process terminated due to signal: '
-      f'{signal.strsignal(signal.SIGUSR1)}'),
+      f'{signal_desc(signal.SIGUSR1)}'),
      ])
 def test_cli_gpg_wrap(tmp_path, caplog, command, expected, match):
     with open(tmp_path / '.key.bin', 'wb') as f: