error[E0463]: can't find crate for `core`- with: `--prefix=/usr --libdir=/usr/lib/amd64`

[psumbera]

Rust build fails when using for bootstrap Rust 1.87.0 built with --prefix=/usr --libdir=/usr/lib/amd64 (On Solaris 64 bit libraries need to be placed into /usr/lib/amd64):

Building compiler artifacts (stage0 -> stage1, x86_64-pc-solaris)
warning: `/builds/psumbera/userland-test/components/rust/rustc/build/.cargo/config` is deprecated in favor of `config.toml`
note: if you need to support cargo 1.38 or earlier, you can symlink `config` to `config.toml`
   Compiling proc-macro2 v1.0.93
   Compiling unicode-ident v1.0.14
   Compiling libc v0.2.169
   Compiling cfg-if v1.0.0
error[E0463]: can't find crate for `core`
  |
  = note: the `x86_64-pc-solaris` target may not be installed
  = help: consider downloading the target with `rustup target add x86_64-pc-solaris`
  = help: consider building the standard library from source with `cargo build -Zbuild-std`

For more information about this error, try `rustc --explain E0463`.
error: could not compile `cfg-if` (lib) due to 1 previous error

This used to work with Rust 1.78.0.

[jieyouxu]

I believe #141729 fixes this for 1.89.0, but not present in 1.87.0

[jyn514]

@jieyouxu should we backport #141729 to 1.88?

[Mark-Simulacrum]

I'm not opposed to a backport but given the long time range not sure it's worth it.

[jieyouxu]

@jieyouxu should we backport #141729 to 1.88?

That's only a beta backport right? Here it's a stable version that is reported. We'd have to do a stable point release, and I don't feel like it's justified alone in absence of other stable backport candidates. And even then I'm not sure if it's worth it, like Mark said.

[jyn514]

That's only a beta backport right? Here it's a stable version that is reported. We'd have to do a stable point release, and I don't feel like it's justified alone in absence of other stable backport candidates. And even then I'm not sure if it's worth it, like Mark said.

right. but we can limit the breakage to only 1.87, instead of breaking both 1.87 and 1.88.

[jieyouxu]

Ok. I think that's reasonable, let me beta-nominate the PR.

EDIT: nvm you were so much faster