Docker bootstrap build reports invalid Ubuntu package signatures

Source: Troubleshooting reference

Symptom: ./tests/run.sh fails during apt-get update with At least one invalid signature was encountered, before running tests.

Possible root cause: A full Docker data disk prevents complete package index writes. On the affected Colima VM, /var/lib/docker was at 100% with zero available space. This observation does not rule out other signature errors.

Confirm: Use colima ssh -- df -h / /var/lib/docker and docker system df to distinguish VM storage exhaustion from host free space.

Fix: After choosing an explicitly authorized cleanup or disk expansion, restore free space and rerun ./tests/run.sh. Do not disable signature checking or treat this pre-test environment failure as a passing suite.

For an isolated test profile, verify the daemon before running the gate:

env -u DOCKER_HOST DOCKER_CONTEXT=colima-PROFILE docker info --format '{{.Name}}'

Replace PROFILE with an existing profile. An inherited DOCKER_HOST can keep Docker pointed at the default socket despite selecting another context.