build: add the check git shell

build/git.sh

@@ -0,0 +1,20 @@
+#!/bin/bash
+
+# Check current branch
+if test "master" != "$(git symbolic-ref --short HEAD)"; then
+  echo 'Not on `master` branch.' >&2;
+  exit 128;
+fi
+
+
+# Check local working tree
+if test -n "$(git status --porcelain)"; then
+  echo 'Unclean working tree. Commit or stash changes first.' >&2;
+  exit 128;
+fi
+
+# Check remote history
+if test "0" != "$(git rev-list --count --left-only @'{u}'...HEAD)"; then
+  echo 'Remote history differ. Please pull changes.' >&2;
+  exit 128;
+fi