Never actually handled optional-ness of Invoke import

Was just silently failing, wahoops

2 files changed, 13 insertions, 0 deletions

diff --git a/paramiko/config.py b/paramiko/config.py
index e6663b71..bef42610 100644
--- a/paramiko/config.py
+++ b/paramiko/config.py
@@ -380,6 +380,10 @@ class SSHConfig(object):
                 exec_cmd = self._tokenize(
                     options, target_hostname, "match-exec", param
                 )
+                # This is the laziest spot in which we can get mad about an
+                # inability to import Invoke.
+                if invoke is None:
+                    raise invoke_import_error
                 # Like OpenSSH, we 'redirect' stdout but let stderr bubble up
                 passed = invoke.run(exec_cmd, hide="stdout", warn=True).ok
             # Tackle any 'passed, but was negated' results from above
diff --git a/tests/test_config.py b/tests/test_config.py
index 16f09c48..7c86667a 100644
--- a/tests/test_config.py
+++ b/tests/test_config.py
@@ -702,6 +702,15 @@ def _expect(success_on):
 
 
 class TestMatchExec(object):
+    @patch("paramiko.config.invoke", new=None)
+    @patch("paramiko.config.invoke_import_error", new=ImportError("meh"))
+    def test_raises_invoke_ImportErrors_at_runtime(self):
+        # Not an ideal test, but I don't know of a non-bad way to fake out
+        # module-time ImportErrors. So we mock the symptoms. Meh!
+        with raises(ImportError) as info:
+            load_config("match-exec").lookup("oh-noes")
+        assert str(info.value) == "meh"
+
     @patch("paramiko.config.invoke.run")
     @mark.parametrize(
         "cmd,user",