Can't use download-ci-llvm any more

[est31]

Enabling download-ci-llvm used to work just fine for me, until today.

After rebasing on top of 7504256 , doing anything with rustc beyond stage 1 fails:

$ ./x.py build
[...]
Building stage1 std artifacts (x86_64-unknown-linux-gnu -> x86_64-unknown-linux-gnu)
[...]
error while loading shared libraries: libLLVM-11-rust-1.49.0-nightly.so: cannot open shared object file: No such file or directory

To verify it's not due to some caching issue caused by my experiments in #79043 that temporarily turned the feature off I deleted the entire build directory. It correctly downloaded the stage0 and llvm artifacts, but still failed when trying to run stage1 rustc.

[est31]

The last commit I was on was 361c4ea

So the regression is somewhere in this range: 361c4ea...7504256

[est31]

cc @Mark-Simulacrum maybe cause was #78986 ?

[Mark-Simulacrum]

Indeed. Posted #79074 to fix this.