Overriding seccomp policy: shm_open

[Jacob Zimmermann]

Hi

I'm trying to get my hands on snapcraft by building a snap of "Hatari"
(Atari ST emulator). I got it working nicely in devmode but it won't run
under strict confinement, specifically it gets killed when attempting to
execute shm_open().

Based on whatever little information I could gather I tried to override
the default policy like so:

apps:
  hatari:
    command: hatari
    plugs: [home, unity7, hatari-permissions]

...

plugs:
  hatari-permissions:
    type: old-security
    security-override:
      syscalls: [shm_open]

But no avail, it just won't let it use this syscall. I couldn't find
anything in the docs about how is it supposed to be done.

Thanks & Best Regards

Jacob