Refactor test-git-no-uncommitted-changes to independent script

.github/workflows/ci-meson.yml

@@ -79,7 +79,7 @@ jobs:
         id: check_update_meson
         run: |
           python3 tools/update-meson.py
-          make test-git-no-uncommitted-changes
+          ./tools/test-git-no-uncommitted-changes
         continue-on-error: true
 
       - name: Show files changed by update-meson

Makefile

@@ -254,13 +254,7 @@ TEST_TARGET = $@
 TEST = ./sage -t --logfile=$(TEST_LOG) $(TEST_FLAGS) --optional=$(TEST_OPTIONAL) $(TEST_FILES)
 
 test-git-no-uncommitted-changes:
-	@UNCOMMITTED=$$(git status --porcelain); \
-	if [ -n "$$UNCOMMITTED" ]; then \
-	    echo "Error: the git repo has uncommitted changes:"; \
-	    echo "$$UNCOMMITTED"; \
-	    echo; \
-	    exit 1; \
-	fi
+	./tools/test-git-no-uncommitted-changes
 
 test: all
 	@echo '### make $(TEST_TARGET): Running $(TEST)' >> $(TEST_LOG)

tools/test-git-no-uncommitted-changes

@@ -0,0 +1,10 @@
+#!/usr/bin/env sh
+# Test that there is no uncommitted changes in the repository. Return failure if there is.
+# Can also be invoked with `make test-git-no-uncommitted-changes` from top level.
+UNCOMMITTED="$(git status --porcelain)";
+if [ -n "$UNCOMMITTED" ]; then
+	echo "Error: the git repo has uncommitted changes:";
+	echo "$UNCOMMITTED";
+	echo;
+	exit 1;
+fi