Example of problem this has just caused me: - Made changes to build-gcc script *and* switched the gcc build task to a docker image based on Debian. - This resulted in a toolchain slighly different from what would have been produced on Centos (for instance, built on Debian, we have a gcc/lib32 path, but that path doesn't exist when built on Centos, it's gcc/lib instead) - I did a subsequent push with the same build-gcc script changes, but *without* the switch to a docker image based on Debian. - The build tasks still got the GCC toolchain with the gcc/lib32 path. The problem is that by the time we compute a hash for the index during transformations, we don't actually have access to the docker image to possibly add its hash to the equation. Dustin, do you have thoughts?

Maybe just pick new names for these new docker images?

(In reply to Dustin J. Mitchell [:dustin] from comment #1) > Maybe just pick new names for these new docker images? And add the docker image name to the hash? That seems footgun-y but less so than the current status quo, so I can get behind this.

Yeah, I'm not sure this case is worth a lot of heroics..

Comment on attachment 8938257 [details] Bug 1426324 - Make toolchain cache indexes vary depending on the docker image name. https://reviewboard.mozilla.org/r/209018/#review214888 ::: taskcluster/taskgraph/transforms/job/toolchain.py:97 (Diff revision 1) > + # the index path as well. Ideally, the content of the docker image itself > + # should have an influence, but at the moment, we can't get that > + # information here. So use the docker image name as a proxy. Not a lot of > + # changes to docker images actually have an impact on the resulting > + # toolchain artifact, so we'll just rely on such important changes to be > + # accompanied with a docker image name change. I like this reasoning :)

Pushed by mh@glandium.org: https://hg.mozilla.org/integration/autoland/rev/f41ca59052be Make toolchain cache indexes vary depending on the docker image name. r=dustin

Had to back this out temporarily to work around bug 1421100 not being deterministic.

Backout by mh@glandium.org: https://hg.mozilla.org/integration/mozilla-inbound/rev/c1e20de19b6f Backout changeset f41ca59052be in an attempt to unbust win32 builds. a=bustage on a CLOSED TREE

Pushed by mh@glandium.org: https://hg.mozilla.org/integration/mozilla-inbound/rev/841178c05781 Make toolchain cache indexes vary depending on the docker image name. r=dustin