I am not sure when the problem started, but one day I was checking the status of dnscrypt-proxy service and noticed that it had crashed and there was little information about it in the System Journal. Just that:
systemd: Created slice Slice /system/systemd-coredump. systemd: Started Process Core Dump (PID 1866/UID 0). systemd-coredump: Process 1033 (dnscrypt-proxy) of user 62582 dumped core. systemd: firstname.lastname@example.org: Deactivated successfully. systemd: dnscrypt-proxy.service: Main process exited, code=killed, status=31/SYS
I had no idea what was causing it.
I spent several days looking for an explanation until I stumbled upon this post:
There, somebody had a similar situation, but with a different service and in an OpenSUSE linux. However the author described the culprit (a line within the service file):
SystemCallFilter=~ ... @privileged ...
So, I decided to try it out… and it worked! If I removed that item from
dnscrypt-proxy.service everything returned to normal. No more crashes!
At the original post the author says:
When the service is killed no useful information is logged to the System Journal. Only
Main process exited, code=killed, status=31/SYS
The manual says:
@privileged All system calls which need super-user capabilities (capabilities(7))
It seems that there is something wrong with
systemd, but I have no clue what it is. Furthermore, I have a version of Manjaro XFCE running in a VirtualBox VM that is very similar to the host machine (that had the dnscrypt-proxy problem) but it is running without problems.
Anyway… I hope that this post can help somebody.