better crash diagnostics in ffmpeg test

script/verify-ffmpeg.py

@@ -41,7 +41,10 @@ def main():
   try:
     test_path = os.path.join(SOURCE_ROOT, 'spec', 'fixtures',
         'no-proprietary-codecs.js')
-    subprocess.check_call([electron, test_path] + sys.argv[1:])
+    env = dict(os.environ)
+    env['ELECTRON_ENABLE_STACK_DUMPING'] = 'true'
+    env['ELECTRON_ENABLE_LOGGING'] = 'true'
+    subprocess.check_call([electron, test_path] + sys.argv[1:], env=env)
   except subprocess.CalledProcessError as e:
     returncode = e.returncode
   except KeyboardInterrupt:

spec/fixtures/no-proprietary-codecs.js

@@ -17,6 +17,11 @@ app.once('ready', () => {
     show: false
   })
 
+  window.webContents.on('crashed', (event, killed) => {
+    console.log(`WebContents crashed (killed=${killed})`)
+    app.exit(1)
+  })
+
   window.loadFile(path.resolve(__dirname, 'asar', 'video.asar', 'index.html'))
 
   ipcMain.on('asar-video', (event, message, error) => {