When building from a released tarball, the build process should not complain about missing `change-id=` in bootstrap.toml

[dilyanpalauzov]

When I download a release tarball - https://static.rust-lang.org/dist/rustc-1.89.0-src.tar.xz - and for it call

$ ./configure --enable-optimize-llvm --enable-extended --llvm-root=/usr/local --enable-profiler --enable-llvm-link-shared --enable-sanitizers --disable-docs --target=x86_64-unknown-linux-gnu --enable-vendor --enable-local-rust
$ x.py build

the system prints:

Building bootstrap
Finished dev profile [unoptimized] target(s) in 0.69s
fatal: not a git repository (or any of the parent directories): .git
WARNING: The change-id is missing in the bootstrap.toml. This means that you will not be able to track the major changes made to the bootstrap configurations.
NOTE: to silence this warning, add change-id = 142379 or change-id = "ignore" at the top of bootstrap.toml

• When building from a released tarball, the build process should not complain about missing change-id= in bootstrap.toml.

[Kobzol]

Hmm, I guess that there are people and distros that do want to track the changes, but still build from source distributions though. So for them it might make sense to first manually modify the bootstrap.toml file with the latest change ID that they saw. But I agree that in the common case the warning doesn't make much sense.

[jieyouxu]

We discussed the change-id warning in #145780 (comment), and my opinion is that this is intended to be upfront to the user. If you would like to silence this warning, you can use a bootstrap.toml with

change-id = "ignore"

to explicitly signal so. I'm going to close this as "not-a-bug" as I rather keep this explicit.