[TASK] Add check before commit that nix files have valid syntax

Makefile

@@ -0,0 +1,24 @@
+MAKEFLAGS += --warn-undefined-variables
+SHELL := $(shell which bash)
+.EXPORT_ALL_VARIABLES:
+.ONESHELL:
+.SHELLFLAGS := -eu -o pipefail -c
+.SILENT:
+
+
+.PHONY: add-pre-commit-hook
+add-pre-commit-hook:
+	printf '#!/bin/sh\nmake test\n' > .git/hooks/pre-commit
+	chmod +x .git/hooks/pre-commit
+
+
+.PHONY: test
+test:
+	echo "Find nix files"
+	find nixos -name "*.nix" | while read f; do
+		echo "Checking $$f"
+		nix-instantiate --parse "$$f" > /dev/null
+	done
+	echo "All files OK"
+
+.DEFAULT_GOAL := test