$ bash --version GNU bash, version 5.0.3(1)-release (x86_64-pc-linux-gnu) $ uname -a Linux penguin 5.4.40-04224-g891a6cce2d44 #1 SMP PREEMPT Tue Jun 23 20:21:29 PDT 2020 x86_64 GNU/Linux
(This is a Pixelbook running the default Crostini Linux VM under Chrome OS 84.0.4147.110. I can reproduce the issue on regular Debian too, though.) To reproduce, run the following commands: shopt -s extdebug trap : DEBUG : < <(:) Now, type any character (e.g., 'a'). At this point, you'll see bash print `exit`, and the shell does indeed exit. Additionally, assuming you ran bash inside another shell, you'll see the 'a' character is echoed. It's a hard to describe clearly, but the result looks like this (`bcat@penguin:pts/0` is the prompt from my outer shell): bcat@penguin:pts/0 J:0 ~ $ bash --norc bash-5.0$ shopt -s extdebug bash-5.0$ trap : DEBUG bash-5.0$ : < <(:) bash-5.0$ [I TYPED 'a' HERE]exit bcat@penguin:pts/0 J:0 ~ $ a The inner shell with the DEBUG trap acts as if it received an EOF on stdin, and exits accordingly, but the 'a' character I typed into my terminal is indeed still there, and it's echoed by the outer shell after the inner shell (wrongly) exits. I wonder if stdin of the inner shell is getting screwed up by the extdebug DEBUG trap somehow. Cheers, Jon
