run command in input.conf doesn't quit anymore

Important Information

Provide following Information:

• mpv version

mpv 0.33.0-31-gb8156a9a86

• Linux Distribution and Version

Ubuntu 20.04.1

• Source of the mpv binary

Compiled locally using mpv-build

• If known which version of mpv introduced the problem

It worked before I upgraded from Ubuntu 18.04 to 20.04, which seems to have updated mpv as well.

• Window Manager and version

i3 version 4.19 (2020-11-15)

Reproduction steps

• Add i run "/bin/sh" "-c" "echo ${working-directory} ${path} | dzen2 -p 1 -y 200" to input.conf.
• Hit 'i' while watching a video
• The dzen2 box doesn't disappear after one second as -p 1 tells it to.
• Calling the above echo ... | dzen2 -p 1 from the command line does work as expected (and used to work in mpv also).

Same problem occurs without using /bin/sh:

My input.conf file used to do it this way:

i run "mpv-info" "${working-directory}" "${path}"

where mpv-info is just a script that calls dzen2 with its -p parameter to automatically exit after a certain period of time. This used to work and a call to mpv-info still works if called from the command line.

Expected behavior

dzen2 -p 1 should self-terminate after one second.

Actual behavior

dzen2 persists longer than one second, persists after mpv is closed, and has to be killed with kill -9

Log file

output.txt

Reproduce the input.conf run command while watching a video, then compare it with the same dzen2 command run directly from the shell. Start with the linked output.txt and the run command entry point; done means dzen2 honors -p 1 and does not remain after mpv exits.