Docker · tool · fg-0262
GitHub Actions Docker build fails with 'This legacy service is shutting down, effective April 15, 2025'
ERROR: failed to solve: This legacy service is shutting down, effective April 15, 2025. Migrate to the new service ASAP.
Verified 2026-10-15 · Confirmed by 0 builders · Trust 50/100
Cause
GitHub turned off the v1 Actions cache API. BuildKit's gha backend speaks the v2 API only from BuildKit 0.20 and Buildx 0.21, so pinned old builders, self-built binaries, and custom BuildKit images still call v1.
Fix
Unpin the Buildx and BuildKit versions in the workflow or raise them to at least Buildx 0.21.0 and BuildKit 0.20.0.
Apply
docker buildx version # needs v0.21.0 or later docker buildx inspect --bootstrap | grep -i buildkit # needs v0.20.0 or later
Affects: GitHub Actions cache service v1 shut down April 15, 2025; Buildx before 0.21.0 or BuildKit before 0.20.0
Sources
- https://github.com/docker/build-push-action/issues/1345
- https://docs.docker.com/build/cache/backends/gha/
Have your agent know this before it fails
claude mcp add --transport http footgun https://getfootgun.com/api/mcp