Notable changes back to v0.20.0:

v0.21.1:
Builtin Dockerfile frontend has been updated to v1.15.1.
Fix buildctl --tlsdir for non-cert-manager.io tls certificate naming. #5950
Fix panic when null cache options were sent using solve grpc API. #5925

v0.21.0:
Builtin Dockerfile frontend has been updated to v1.15.0. changelog
Runc container runtime has been updated to v1.2.6. #5845
The cache manifest created by --cache-to now defaults to OCI artifact manifest (instead of OCI image index). For old behavior, set image-manifest=false. #5864
The cache timeout for registry credentials has been reduced from 10 min to 5 min. #5859
Buildctl --tlsdir option now allows filenames compatible with cert-manager.io. #5886
Update free-space filter GC/prune filter to not remove all data when no max-space value is set. #5827
Mitigate GitHub Actions cache v2 flakiness. #5805
Add autoallow and entitlements support to CDI devices. #5742
Support authentication in LLB for Git and HTTP. #5733
Support for adding additional request header fields for HTTP sources. #5732
OpenTelemetry traces now contain spans for layer extraction. #5831
containerd image exporter creates dangling images by default. #5858
Add support for bind and cache mounts for WCOW. #5708
Add session exporter capability. #5907 #5908
Add metadata-only transfer option for local source. #5897
Fix X mode to be Linux-compatible for file operations using chmod. #5850
Fix --chmod when applied to parent directories. #5788
Fix missing user-agent when buildkit requests layers from the registry. #5834
Fix missing user-agent for GitHub Actions importer. #5759 #5760
Fix reading secrets from any session on parallel build requests. #5833
Fix race condition causing "file used by another process" errors with WCOW. #5885

v0.20.2:
Fix possible UID overflow when setting user for container #5844 GHSA-265r-hfxg-fhmg
update RootlessKit to v2.3.4 #5825

v0.20.1:
Builtin Dockerfile frontend has been updated to v1.14.1
Fix panic during CDI manager initialization. #5769 cncf-tags/container-device-interface#254
Fix gRPC message size when writing SBOMs. #5798 containerd/containerd#11457
Fix possible panic with libc-bin emulation in QEMU v9.2.0. #5808
Update azblob client retries for GitHub Actions cache backend. #5797 tonistiigi/go-actions-cache#33

Upgrade areas:

• gitlab-cloud-runners
• WMCS and Trusted runners
• buildctl referenced by kokkuri