Try forcing the commit

.github/workflows/main.yml

@@ -6,8 +6,6 @@ jobs:
     steps:
       - name: Checkout
         uses: actions/checkout@v2
-        with:
-          fetch-depth: 2
       - name: Install dependencies
         run: npm install
       - name: Lint

dist/index.js

@@ -42756,7 +42756,13 @@ strategies.HTTPOrNetworkError = __webpack_require__(951)(strategies.HTTPError, s
 
 
 /***/ }),
-/* 690 */,
+/* 690 */
+/***/ (function(module) {
+
+module.exports = eval("require")("@actions/github");
+
+
+/***/ }),
 /* 691 */
 /***/ (function(module) {
 
@@ -54091,6 +54097,8 @@ function write(key, options) {
 
 exports.__esModule = true;
 var core = __webpack_require__(470);
+var github = __webpack_require__(690);
+var context = github.context;
 var isTrue = function (variable) {
     var lowercase = variable.toLowerCase();
     return (lowercase === '1' ||
@@ -54213,6 +54221,9 @@ var buildExec = function () {
     if (overrideCommit) {
         execArgs.push('-C', "" + overrideCommit);
     }
+    else {
+        execArgs.push('-C', "" + context.sha);
+    }
     if (overridePr) {
         execArgs.push('-P', "" + overridePr);
     }

src/buildExec.ts

@@ -1,4 +1,7 @@
 const core = require('@actions/core');
+const github = require('@actions/github');
+
+const context = github.context;
 
 const isTrue = (variable) => {
   const lowercase = variable.toLowerCase();
@@ -128,6 +131,8 @@ const buildExec = () => {
   }
   if (overrideCommit) {
     execArgs.push('-C', `${overrideCommit}`);
+  } else {
+    execArgs.push('-C', `${context.sha}`);
   }
   if (overridePr) {
     execArgs.push('-P', `${overridePr}`);

src/index.ts

@@ -1,5 +1,6 @@
 const core = require('@actions/core');
 const exec = require('@actions/exec');
+
 const fs = require('fs');
 const request = require('requestretry');