"Building flutter tool..." stuck when I run "flutter doctor"

Question

% flutter doctor
Downloading Dart SDK from Flutter engine 241c87ad800beeab545ab867354d4683d5bfb6ce...
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100  200M  100  200M    0     0  4039k      0  0:00:50  0:00:50 --:--:--  829k
Building flutter tool...
// HANGS HERE

I was waiting for 30minutes. But it was no response.

At first, I upgraded flutter. and met "Building flutter tool..." stuck. So I reinstalled flutter SDK. and ran "flutter doctor" after installing flutter SDK. But I met "Building flutter tool..." stuck too.

When I push Ctrl-C to stop command, it shows

Unable to 'pub upgrade' flutter tool. Retrying in five seconds ... (9 tries left)

I'm in Korea. It is not a country issue. What should I do?

Answer 1

I just RUN on the flutter folder and solved.

• git clean -xfd
• git stash save --keep-index
• git stash drop
• git pull
• flutter doctor