What the fuck is systemd doing
Just start the god damn program and behave normal for once

@AtuM I just want to run an application, and if I run the ExecStart manually with the same environment variables and in the same directory it works just fine

But if it's a service it behaves completely randomly
I'm just gonna run it manually for now and cry about it to my other colleagues

There were some params you probably have set on your bashrc or profile or whatever that systemd doesn't have defined.
Maybe check and see if that's the case?

@NoMad environment variables aren't changed at all, I don't get it
It's some cryptic error of a network library inside the application

I'm just running them manually with 4 SSH sessions and ask my colleagues who know about that library

@LotsOfCaffeine python env? Then you may have versioning issues too. Afaik systemd doesn't follow the normal user routines. Overall, it's not your fault. Systemd is... Special.

@NoMad it's not python, were doing good ol' C++

And yeah I noticed weird things with systemd, but one colleague of the time kind of praised it so I'll ask him if he knows anything

no