Solaris's /bin/sh is not POSIX, don't use set -e for it.

unit_tests/check_common.sh

@@ -1,5 +1,9 @@
 #!/bin/sh
-set -e
+
+# Solaris's /bin/sh is not a POSIX shell, and
+# it quits when cd fails, even if it is followed by a ||
+# So enable -e only on POSIX shells
+(cd /nonexistentdir || true) && set -e
 
 WRAPPER=${WRAPPER-}
 TOP=`pwd`/..