Issue with using signal 20 in terminal (ctrl-z)

[half1red]

There seems to be an issue with the use of ctrl-z (20 - SIGTSTP ) in a terminal with pyinstaller 3.4.

Steps to reproduce :
in a file main.py :

x = input()

print(x)

pyinstaller -d all main.py

Ctrl-z to send signal 20 before answering to the input().

The terminal shows the following line and stop responding.

^Z[31603] LOADER: Forwarding signal 20 to child pid 31604

I find the same bug in the latest development version. But it works normally with a previous development version (PyInstaller==3.4.dev0+ab8fd9753)

I don't know it there is any link with #3515.

Ctrl-c works fine.

Please let me know if you need more information.