Describe the bug

After the launcher files were updated in 8d2acb5 (0.3.5), processes spawned from the "w" launchers can't be killed anymore. I am facing this issue when trying to spawn and kill the processes from a NodeJS context. Calling childprocess.kill() via NodeJS's child_process module returns success, but the python process keeps running.

This is a major problem for me, because my NodeJS application (GUI application via NW.js / Electron) is running a python CLI application built with the distlib launcher executables, and it needs to use the "w" launchers, because otherwise a console window pops up, which is bad for the user experience.

0.3.3 is the most recent release which is working fine.

0.3.4 had the immediate 3221225477 / 0xC0000005 exit code error, and I already had to ignore this version when building standalone installers of my python application. Fortunately, pip had reverted back to distlib 0.3.3 until recently, so installing via pip was no problem either, but now it has merged the distlib 0.3.5 release, which is once again bad, and the issue needs to be fixed.
Related (old 0.3.4 issue): takluyver/pynsist#243 (comment)

Apparently, these are the recent launcher changes:
https://bitbucket.org/vinay.sajip/simple_launcher/commits/

To Reproduce

I've created a reproduction repo (already did this for 0.3.4). Please see the build config and build+run scripts for the 0.3.5 issue:
https://github.com/bastimeyer/distlib-bug/tree/53f520efec1a6173b7ca037d26c89a6dec8ca633

The resulting GH action logs:
https://github.com/bastimeyer/distlib-bug/actions/runs/2718462897

0.3.5-t64 (success): https://github.com/bastimeyer/distlib-bug/runs/7467911880?check_suite_focus=true#step:7:1
0.3.5-w64 (failure): https://github.com/bastimeyer/distlib-bug/runs/7467912062?check_suite_focus=true#step:7:1

0.3.3-t64 (success): https://github.com/bastimeyer/distlib-bug/runs/7467911132?check_suite_focus=true#step:7:1
0.3.3-w64 (success): https://github.com/bastimeyer/distlib-bug/runs/7467911332?check_suite_focus=true#step:7:1

Environment

• OS, including version: Windows (any)
• Version of this library: 0.3.5