Pass to warning uncaught exceptions (#359)

src/cache-save.ts

@@ -4,6 +4,14 @@ import fs from 'fs';
 import {State} from './constants';
 import {getCacheDirectoryPath, getPackageManagerInfo} from './cache-utils';
 
+// Catch and log any unhandled exceptions.  These exceptions can leak out of the uploadChunk method in
+// @actions/toolkit when a failed upload closes the file descriptor causing any in-process reads to
+// throw an uncaught exception.  Instead of failing this action, just warn.
+process.on('uncaughtException', e => {
+  const warningPrefix = '[warning]';
+  core.info(`${warningPrefix}${e.message}`);
+});
+
 export async function run() {
   try {
     const cacheLock = core.getInput('cache');