Add locale check script + CI job, that runs gettext check

.github/workflows/lint.yml

@@ -71,6 +71,18 @@ jobs:
     - name: Type check with mypy
       run: mypy
 
+  locale-check:
+    runs-on: ubuntu-latest
+
+    steps:
+    - uses: actions/checkout@v4
+    - name: Install dependencies
+      run: |
+        sudo apt-get update
+        sudo apt-get install gettext
+    - name: Check locale files with gettext
+      run: make locale-check
+
   docs-lint:
     runs-on: ubuntu-latest
 

Makefile

@@ -4,7 +4,7 @@ PYTHON ?= python3
 all: format style-check type-check doclinter test
 
 .PHONY: check
-check: style-check type-check doclinter
+check: style-check type-check locale-check doclinter
 
 .PHONY: clean
 clean: clean
@@ -56,6 +56,10 @@ format:
 type-check:
 	@mypy
 
+.PHONY: locale-check
+locale-check:
+	@$(MAKE) -C sphinx/locale check
+
 .PHONY: doclinter
 doclinter:
 	@sphinx-lint --enable all --disable triple-backticks --max-line-length 85 --sort-by filename,line \

sphinx/locale/Makefile

@@ -0,0 +1,11 @@
+# Ignore locales that are known failures. See utils/babel_runner.py
+IGNORED = ta
+POFILES = $(wildcard */LC_MESSAGES/sphinx.po)
+CHECK   = $(POFILES:.po=.check)
+
+.PHONY: check
+check: $(filter-out $(IGNORED:=/LC_MESSAGES/sphinx.check),$(CHECK))
+
+.PHONY: $(CHECK)
+$(CHECK): %.check: %.po
+	msgfmt --check -o /dev/null $<