When I hit run button for Flutter app then IDE Intellij IDEA shows a message on console “Waiting for another flutter command to release the startup lock…”
Nothing happens after message.
Stop any instance of flutter IDE’s ([IntelliJ]/[Android Studio]/[VS Code]) and check for the existence of a file named
lockfile in location
[flutter_installation_folder]/bin/cache/. If any, delete it and restart your favorite IDE.
In my case, following command in Terminal or cmd helped (as suggested by Günter):
killall -9 dart
On Windows (as suggested by upupming):
taskkill /F /IM dart.exe
or remove this file
<YOUR FLUTTER FOLDER>/bin/cache/lockfile
This releases the occupied lock and makes you able to run other commands.