-# Remove dependency_libs from output.
-sed "s/^dependency_libs=.*/dependency_libs=''/" < "$output.tmp" > "$output"
-chmod --reference="$output.tmp" "$output"
-rm "$output.tmp"
+if [ -n "$output" ]; then
+ mv "$output" "$output.tmp"
+
+ # Remove dependency_libs from output.
+ sed "s/^dependency_libs=.*/dependency_libs=''/" < "$output.tmp" > "$output"
+ chmod --reference="$output.tmp" "$output"
+ rm "$output.tmp"
+fi