-# Don't declare a version "dirty" merely because a time stamp has changed.
-git update-index --refresh > /dev/null 2>&1
+# Test whether to append the "-dirty" suffix only if the version
+# string we're using came from git. I.e., skip the test if it's "UNKNOWN"
+# or if it came from .tarball-version.
+if test -n "$v_from_git"; then
+ # Don't declare a version "dirty" merely because a time stamp has changed.
+ git update-index --refresh > /dev/null 2>&1