swc-installation-test-2.py: Don't print duplicate exceptions

For example, if you have an outdated 'python', you only want to hear
about that once, not once for each PythonPackageDependency.

diff --git a/swc-installation-test-2.py b/swc-installation-test-2.py
index f307e8af8b7496710745f7e7009050c8c0341d8f..3a1b9c4299fca862ed02da8110cec5a9fbbfe19c 100755 (executable)
--- a/swc-installation-test-2.py
+++ b/swc-installation-test-2.py
@@ -97,9 +97,12 @@ def check(checks=None):
             _sys.stdout.write('pass\n')
     if failures:
         print('\nFailures:')
+        printed = []
         for failure in failures:
-            print()
-            print(failure)
+            if failure not in printed:
+                print()
+                print(failure)
+                printed.append(failure)
         return False
     return True