print errno when reporting a system call error

diff --git a/t/perf/p0000-perf-lib-sanity.sh b/t/perf/p0000-perf-lib-sanity.sh
index cf8e1efce7cd29679c3ffdb2fa7d03489c38c1c9..002c21e52a6763ee14ac243b2b3a1af242fc2834 100755 (executable)
--- a/t/perf/p0000-perf-lib-sanity.sh
+++ b/t/perf/p0000-perf-lib-sanity.sh
@@ -33,6 +33,8 @@ test_perf 'export a weird var' '
        test_export bar
 '
 
+test_perf 'éḿíẗ ńöń-ÁŚĆÍÍ ćḧáŕáćẗéŕś' 'true'
+
 test_expect_success 'test_export works with weird vars' '
        echo "$bar" &&
        test "$bar" = "weird # variable"