Continuous Ctrl+C freezes Bash started via git-cmd

[bviktor]

Start a bash session with

c:\git\git-cmd.exe --command=usr\bin\bash.exe --login -i

Then keep pressing Ctrl+C. Within a minute (it's random, sometimes it's 2 seconds, sometimes it's 30) the shell will freeze and no longer respond to user input. Within another minute or so it'll return the prompt and display everything that's been typed in the meanwhile.

Always reproducible for me. Tested with 64 bit Git 2.4.5.1 on Windows 8.1 x64 and Windows 10 x64.

Related: #205

[dscho]

I just tried it and can reproduce it. Unfortunately, I do not have enough time to look into it.

[harriha]

I'm seeing the same with latest 2.5.1. Seeing this occasionally, mostly when I have a file watcher such as chokidar-cli or nodemon running, exiting the process is painfully difficult.

Seen on Windows 10 and Windows 7 today.

[ashelley]

Hello,

I would like to confirm that I'm having this issue still on git 2.6.1 on windows 10.

Symptoms:

pressing ctrl+c when a program is running sporadically takes 10-60 seconds to return to the prompt. The process is killed instantly (but you can't really tell) and the time it takes for the $ prompt to show up is prolonged.

Here is how i can reproduce it albeit not a very minimal test case.

Step 1) make sure you have node installed (I don't think it matters what version since I believe this is a git-bash issue it seems)

Step 2) make sure you have node-dev installed (npm install -g node-dev), details below

Step 3) use this script app.js:

function run() {
   console.log('waiting 5 seconds');
   setTimeout(function() {
      run();
   }, 5000)
}
run();

Step 4) show that node works with ctrl+c (no delay issues)

$ node app.js
waiting 5 seconds
waiting 5 seconds
waiting 5 seconds
waiting 5 seconds
<ctrl+c>

Process exits normally here

Step 5) run with node-dev (sporadic delay issues). This might exit and return you to the command prompt right away but often it takes a long delay to get back to the command prompt

$ node-dev app.js
waiting 5 seconds
waiting 5 seconds
waiting 5 seconds
waiting 5 seconds
<ctrl+c>

If you hit ctrl+c right away it seems more likely it will exit fine. However after letting this loop a couple of times it seems to pretty consistently exhibit the "delay problem"

internally node-dev uses https://nodejs.org/docs/latest/api/fs.html#fs_fs_watchfile_filename_options_listener

which correlates to what @harriha has reported.

I know node has nothing to do with git but I just wanted to post my testcase so that it might help someone reproduce or confirm a fix.

-Adam

[dscho]

@ashelley thank you. This test case will indeed be incredibly valuable to verify a fix.

[laggingreflex]

Cygwin's bash.exe has the same issue. Does this (git-for-windows) use the same bash.exe as Cygwin's, or do they both have a same source? If so, the problem would be linked to it.

Similar issues for Cygwin's bash have been reported: http://google.com/search?q=cygwin+Ctrl-C

[dscho]

Does this (git-for-windows) uses the same bash.exe as Cygwin's

Yes. See https://github.com/git-for-windows/git/wiki#about for details.

[clintwood]

I'm having same issue with nodemon - using Sysinternals Process Explorer I notice that the process tree initially looks like this:

Then running nodemon it looks like this (notice that it has spawned sh.exe as a root process which is not in the original process tree below bash.exe):

Then after Ctrl-c it looks like this (notice that sh.exe is an orphaned process and not part of the original process tree):

Finally after about 60s the orphaned process (sh.exe) terminates and the prompt returns.

Prior to gfw 2.x sh.exe always existed in the process tree below bash.exe. Lastly I also noticed that uname.exe and a few other utility processes are all created as root processes which was not the case in pre 2.x gfw. Hope this helps!

[clintwood]

BTW this is not unique to git-bash.exe. I have the same issue using either bash.exe or sh.exe from via ConEmu. And it's really annoying... ;)

EDIT: @dscho any short term workarounds for this?

[SystemDisc]

In MinTTY, when using Ctrl+C to exit an HTTP server running in Node.JS, node.exe is always left open.
In ConEmu, when using Ctrl+C to exit an HTTP server running in Node.JS, node.exe occasionally hangs before closing, and an sh.exe sometimes hangs, too.

I'd like to also note that I've experienced all of the issues listed above, and that these issues have been happening for me since long before Git for Windows replaced MSYSGit

[dscho]

I believe that I fixed this with b7a95d0