1529587 - Disable sccache when building with --enable-profile-use

Status: RESOLVED WONTFIX

(Firefox Build System :: General, enhancement)

Description

[Michael Shal [:mshal]]

Bug 1490218 disabled sccache for the single tier PGO build, but the 3-tier profile-use stage is triggered via --enable-profile-use instead of setting MOZ_PGO=1. We should disable sccache for this stage because we expect the profile to be different for every build.

Comment 1

[Michael Shal [:mshal]]

Attachment: Bug 1529587 - Disable sccache with --enable-profile-use; r?#firefox-build-system-reviewers

3-tier PGO builds work by setting --enable-profile-use rather than
setting MOZ_PGO=1 in the environment. We should disable sccache when a
PGO build is enabled via this mechanism, since these objects won't be
cached anyway.

Comment 2

[Mike Hommey [:glandium]]

Note that since bug 1490218, IIRC sccache was fixed for the instr part, and we should be able to revert that change for the MOZ_PGO builds.

Comment 3

[Michael Shal [:mshal]]

(In reply to Mike Hommey [:glandium] from comment #2)

Note that since bug 1490218, IIRC sccache was fixed for the instr part, and we should be able to revert that change for the MOZ_PGO builds.

Yeah we have sccache enabled on the instr part of the 3-tier PGO builds, and according to the stats it works fine. We could turn it on for the instr part of the existing 1-tier PGO builds, but that will happen anyway as we finish porting Linux & Windows to the 3-tier model.

Comment 4

[Michael Shal [:mshal]]

glandium mentioned in the review that we can remove the sccache toolchain as a dependency on the toolchain task. That will be handled as part of bug 632954