If any of multiple cache-from fetches fail, caches don't seem to work at all

[vegai]

On docker-20.10.14.

github.com/docker/buildx v0.8.2 
6224def4dd2c3d347eee19db595348c50d7cb491

I'm witnessing a case where we have multiple --cache-from clauses, each referring to localhost images pulled before. If any of these images don't exist already, docker tries to unsuccessfully pull them, e.g.

#12 importing cache manifest from localhost/company/deployment-build:master
#12 ERROR: failed to do request: Head "http://localhost/v2/company/deployment-build/manifests/master": dial tcp 127.0.0.1:80: connect: connection refused

This consistently leads to layer caching not working at all, even for the cache-froms that do exist and were successfully imported.

[tonistiigi]

This error should be non-fatal and your build should continue on. You should see other similar lines for other cache sources.