tests: grep portability fixes

diff --git a/t/t5300-pack-object.sh b/t/t5300-pack-object.sh
index 3a0ef8759c9d7a55b95c56ca38cd3c37ac2432fa..b335c6b42de59b9632ff29693c2d7c75dae9794a 100755 (executable)
--- a/t/t5300-pack-object.sh
+++ b/t/t5300-pack-object.sh
@@ -272,7 +272,8 @@ test_expect_success \
 
 test_expect_success \
     'make sure index-pack detects the SHA1 collision' \
-    'test_must_fail git index-pack -o bad.idx test-3.pack'
+    'test_must_fail git index-pack -o bad.idx test-3.pack 2>msg &&
+     grep "SHA1 COLLISION FOUND" msg'
 
 test_expect_success \
     'honor pack.packSizeLimit' \