CI: unset NO_DOWNLOAD_CI_LLVM for 2 windows jobs

[MarcoIeni]

mati865 mentioned in #132721 (comment) that we can remove this environment variable

try-job: dist-i686-mingw
try-job: dist-x86_64-mingw

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[MarcoIeni]

@bors try

[bors]

⌛ Trying commit 70760ec with merge f9612b3...

[bors]

💔 Test failed - checks-actions

[mati865]

I don't know how this works, but perhaps the dist build without that ENV has to be completed first so it can upload the artifacts?

[Kobzol]

It seems to me from the CI logs that dist-i686-mingw and friends does upload the built dist artifacts, including LLVM. But I guess it's worth a try to first only run the dist jobs without the env. variable.

[MarcoIeni]

@bors try

[bors]

⌛ Trying commit 70760ec with merge 39e570d...

[MarcoIeni]

I'm trying the jobs dist-i686-mingw and dist-x86_64-mingw. Not sure if I understood correctly your suggestion 🤔

[bors]

☀️ Try build successful - checks-actions
Build commit: 39e570d (39e570da40a97a744e222c4961f360b8bd7376f8)

[MarcoIeni]

[Kobzol]

It doesn't look like this does anything for CI time though. Let's try again to see if some cache kicks in.

@bors try

[bors]

⌛ Trying commit 4d80c65 with merge 16dbc3e...

[bors]

☀️ Try build successful - checks-actions
Build commit: 16dbc3e (16dbc3e8c76043dea5056f4071bf2849e9c0e57d)

[Kobzol]

Doesn't seem like there is any CI time effect.

[mati865]

Doesn't seem to work: [TIMING] core::build_steps::llvm::Llvm { target: x86_64-pc-windows-gnu } -- 859.128

[mati865]

Ah, it also doesn't work for MSVC. Probably a general Windows problem.

[MarcoIeni]

Since it doesn't work and it doesn't make a big impact on timings, I'll close this PR 👍

[mati865]

So this is the reason why it doesn't work with MSVC:

rust/src/ci/scripts/install-clang.sh

Line 67 in a8e75c5

ciCommandSetEnv NO_DOWNLOAD_CI_LLVM 1

Do you want to give it another try or should I open a PR?

[MarcoIeni]

go for it :)

[MarcoIeni]

Btw the logs for the try job of dist-x86_64-mingw show that the group "Building LLVM for x86_64-pc-windows-gnu" took 14 minutes. So it seems that we aren't downloading llvm. Maybe it's because we detect that it changed (based on this)?

Also, I found this comment that suggests that we should keep this ENV variable for dist builders. Do you agree?

[Kobzol]

Dist builders are designed to build the components, and other jobs (and tools like rustup etc.) are designed to download them. So we should keep building them on the dist builders. In theory, we could just build them from time to time, but I don't think I trust our CI enough to do that at the moment.

[MarcoIeni]

FYI I tried downloading llvm in mingw but it fails