In the process of cherry-picking a bunch of stuff onto the 1.25.x-twtr branch I ran into an issue that I can repro on my local master. Steps to repro are 1.

git checkout master

2.

./v2 fmt ::

3.

Ctrl-c

while that is running. For me the pants process is unkillable with Ctrl-c. I bisected a version of this issue on my local 1.25.x-twtr branch and it seems to be introduced in https://github.com/pantsbuild/pants/pull/9674 If someone could give this repro a shot on theit machine, I will make an issue for it once its confirmed not just my machine.