Waiting for another flutter command to release the startup lock

Question

When I run my flutter application it show

Waiting for another flutter command to release the startup lock

this messages and not

Answer 1

You can try to all flutter processes.

TL;DR - go to point 4)

1) List of the processes:

ps aux

2) Search name containing with flutter:

ps aux | grep flutter

where output can be like there:

stackoverflow     16697   1.5  0.0  4288316    704   ??  S    10:02PM   0:15.80 bash /flutter_path/flutter/bin/flutter --no-color build apk
stackoverflow      2800   1.5  0.0  4288316    704   ??  S     9:59PM   0:18.49 bash /flutter_path/flutter/bin/flutter --no-color pub get
stackoverflow      1215   1.5  0.0  4280124    700   ??  S     9:58PM   0:18.89 bash /flutter_path/flutter/bin/flutter --no-color config --machine
stackoverflow      8449   1.5  0.0  4296508    716   ??  S    10:00PM   0:17.20 bash /flutter_path/flutter/bin/flutter --no-color pub get
stackoverflow      1326   1.4  0.0  4288316    708   ??  S     9:58PM   0:18.97 bash /flutter_path/flutter/bin/flutter daemon
stackoverflow     16687   0.0  0.0  4279100    820   ??  S    10:02PM   0:00.01 bash /flutter_path/flutter/bin/flutter --no-color build apk
stackoverflow      8431   0.0  0.0  4288316    804   ??  S    10:00PM   0:00.02 bash /flutter_path/flutter/bin/flutter --no-color pub get
stackoverflow      2784   0.0  0.0  4288316    704   ??  S     9:59PM   0:00.01 bash /flutter_path/flutter/bin/flutter --no-color pub get
stackoverflow      1305   0.0  0.0  4280124    712   ??  S     9:58PM   0:00.01 bash /flutter_path/flutter/bin/flutter daemon
stackoverflow      1205   0.0  0.0  4279100    788   ??  S     9:58PM   0:00.01 bash /flutter_path/flutter/bin/flutter --no-color config --machine
stackoverflow     11416   0.0  0.0  4268176    536 s000  R+   10:18PM   0:00.00 grep --color flutter

3) Get processes ID

We need content from second column (from above output):

ps aux | grep flutter | awk '{print $2}'

4 a) Kill "automatically":

To list, search and kill all of them you can use

kill $(ps aux | grep flutter | grep -v grep  | awk '{print $2}')

(you can run it also with sudo)

or

ps aux | grep flutter | grep -v grep | awk '{print $2}' | xargs kill -15

4 b) Kill manually

You can kill processes one-by-one using:

sudo kill -15 <process_ID>

e.g. to kill process with id 12345 use:

sudo kill -15 13245

If -15 will not work, you can try -2 or -1.

Final option it is -9 which should not be used because it prevents the process from doing any cleanup work.

Answer 2

I have the same issue, I tried all the above solutions, but none of them worked for me. Then I searched the keywords in flutter directory, and found the following code. So I tried to delete bin/cache/.upgrade_lock, and it worked finally.

Answer 3

I also faced same issue i followed the best and the easiest way

Environment : Windows

IDE : Android Studio

Tools>flutter(last option)> select flutter clean

after flutter clean finished you all set and good to go.

Answer 4

1. Stop all running dart instances

If you're using Android Studio save your work and close it. And open your terminal to kill running dart instances.

Linux:

killall -9 dart

Windows:

taskkill /F /IM dart.exe

2. Remove lockfile

You can find lockfile inside flutter installation directory.

<flutter folder>/bin/cache/lockfile

Answer 5

Remove this file:

<YOUR FLUTTER FOLDER>/bin/cache/lockfile

This releases the occupied lock and makes you able to run other commands.

Answer 6

I have tried all of below steps, but none worked.

1. Delete lockfile;
2. Run killall -9 dart;
3. Restart my PC.

Below is the final command that worked for me

rm -rf <flutter_dir>bin/cache/.upgrade_lock