Troubleshooting

The failures people actually hit, and what they mean.

"Apple Containers can't run on this Mac"

It needs an Apple silicon Mac running macOS 26. The vmnet APIs that give containers their own addresses do not exist earlier. Use a Docker engine instead — Hopper still works as a client.

The engine says "stopped" and Start does nothing

Check what Apple's own services think:

container system status
container system start

If system start complains about a kernel, let it install one:

container system start --enable-kernel-install

Hopper always passes that flag, because the command otherwise prompts on stdin and Hopper has no terminal to answer with.

Postgres exits immediately on Apple Containers

Its data directory is not empty. Apple's named volumes are real ext4 filesystems and arrive with a lost+found, which Postgres refuses to initialise into. Point PGDATA at a subdirectory:

environment:
  PGDATA: /var/lib/postgresql/data/pgdata

Something bind-mounts /var/run/docker.sock and fails

Portainer, Traefik's Docker provider, and most CI-in-a-container setups do this. Apple publishes no Docker socket, so there is nothing to mount. These need a Docker engine.

"no matching manifest for linux/arm64"

An x86-only image. Ask for it explicitly:

container run --platform linux/amd64 someimage

The Stacks tab disappeared

You are on Apple Containers, which has no Compose. See Stacks.

Permission denied on the socket (Linux)

You are not in the docker group:

sudo usermod -aG docker "$USER"   # then log out and back in

For rootless Podman, the socket needs starting:

systemctl --user start podman.socket

Hopper connects to the wrong daemon

DOCKER_HOST wins over everything when it is set. Unset it, or set HOPPER_ENGINE to pick a provider explicitly:

HOPPER_ENGINE=apple /Applications/Hopper.app/Contents/MacOS/hopper

Checking the app is really notarized

spctl -a -t exec -vv /Applications/Hopper.app
# accepted / source=Notarized Developer ID

Checking the .dmg instead will report no usable signature even on a perfectly good release — the DMG is not codesigned, the ticket is stapled to it, and the signature lives on the app inside.