Docker cache is not being used

[lebeg]

As can be seen for all latest builds: docker cache is not being reused and images are always getting rebuild. This is due to the ccache change #11151

The problem is that due to multiheaded docker build the first build does not get a tag and is considered an intermediate layer.

The --cache-from parameter in build.py restricts the cache only to tagged images and that leads to rebuilds.

[lebeg]

I don't have permissions to add labels, but I believe that this should be tagged with the CI label.

[ThomasDelteil]

https://jenkins.mxnet-ci.amazon-ml.com/blue/organizations/jenkins/incubator-mxnet/detail/PR-11210/8/pipeline something is happening with ccache is it related or a different issue?

[lebeg]

@ThomasDelteil it is indeed related to ccache, but is a different error

[lebeg]

thanks @ThomasDelteil for the link!

[kalyc]

@sandeep-krishnamurthy could you add label "CI", "Docker" to this?

[lebeg]

The issue should have been fixed by #11302