Tools are not available on cross compiled platforms since #61861

[mati865]

Moved from rust-lang/rust-clippy#4267

#61861 was merged in #61962, since then Rustfmt fails to build when cross compiling which is the case for almost all non Tier 1 platforms.
Clippy and RLS are failing with similar error.

Error on aarch64-unknown-linux-gnu:

[01:14:03] error[E0464]: multiple matching crates for `rustc_macros`
[01:14:03]   --> /cargo/registry/src/github.com-1ecc6299db9ec823/rustc-ap-rustc_target-491.0.0/abi/mod.rs:10:5
[01:14:03]    |
[01:14:03]    | use syntax_pos::symbol::{sym, Symbol};
[01:14:03]    |     ^^^^^^^^^^
[01:14:03]    |
[01:14:03]    = note: candidates:
[01:14:03]            crate `rustc_macros`: /checkout/obj/build/x86_64-unknown-linux-gnu/stage1/lib/rustlib/x86_64-unknown-linux-gnu/lib/librustc_macros-97bf1e9c420f9886.so
[01:14:03]            crate `rustc_macros`: /checkout/obj/build/x86_64-unknown-linux-gnu/stage1-tools/release/deps/librustc_macros-2f4546e1163449fb.so
[01:14:03] 
[01:14:03] error[E0461]: couldn't find crate `rustc_macros` with expected target triple x86_64-unknown-linux-gnu which `syntax_pos` depends on
[01:14:03]   --> /cargo/registry/src/github.com-1ecc6299db9ec823/rustc-ap-rustc_target-491.0.0/abi/mod.rs:10:5
[01:14:03]    |
[01:14:03] 10 | use syntax_pos::symbol::{sym, Symbol};
[01:14:03]    |     ^^^^^^^^^^
[01:14:03]    |
[01:14:03]    = note: the following crate versions were found:
[01:14:03]            crate `rustc_macros`, target triple aarch64-unknown-linux-gnu: /checkout/obj/build/x86_64-unknown-linux-gnu/stage1-tools/aarch64-unknown-linux-gnu/release/deps/librustc_macros-55389246a2ce204b.so
[01:14:03] 
[01:14:03] error: aborting due to 2 previous errors

https://api.travis-ci.com/v3/job/209363492/log.txt

@rustbot modify labels: T-dev-tools A-rustbuild

[mati865]

@rustbot modify labels: T-dev-tools A-rustbuild

[Manishearth]

Why does Clippy depend on rustfmt? We only have it in our Travis tests, and even then a test-fail shouldn't cause an unshipped tool

[mati865]

Modified issue description, it depends on fmt_macros but the error is basically the same.

[its-pointless]

only way i got it to build cross tools was from example in original post copying librustc_macros-97bf1e9c420f9886.so over librustc_macros-2f4546e1163449fb.so
this and suddenly rust nightly std library doubling in size... fun times.

[asomers]

ping. Any progress here? This issue blocks tier2 users from upgrading past rustc nightly 1.36.0.

[Manishearth]

I can't tell where the logs for Clippy on cross platforms are so I don't know how to fix this. Rust has a ton of builders :/

[mati865]

@Manishearth logs for last successful merge: https://dev.azure.com/rust-lang/e71b0ddf-dd27-435a-873c-e30f86eea377/_apis/build/builds/4613/logs/937?&api-version=5.0-preview

It still fails with the same error.

[Manishearth]

Hmm that seems like the rust build system being brittle. I've seen that kind of error before, it's usually solved by deleting something in the build dir.

cc @alexcrichton @pietroalbini