Access to /dev/shm is explicitely blacklisted for sandboxed apps, which means using --filesystem=/dev/shm does not expose JACK sockets to the sandbox; and neither does --device=all.
A special --device=shm permission will land in Flatpak 1.6.1 to support the workaround, but the longer term solution is to use PipeWire through its JACK extension.
Access to
/dev/shm
is explicitely blacklisted for sandboxed apps, which means using--filesystem=/dev/shm
does not expose JACK sockets to the sandbox; and neither does--device=all
.A special
--device=shm
permission will land in Flatpak 1.6.1 to support the workaround, but the longer term solution is to use PipeWire through its JACK extension.This issue is blocked by https://github.com/flatpak/flatpak/issues/1509.