build failure of openssl-sys on illumos within rustup project

[Rustin170506]

For more context - rust-lang/rustup#3263 and sfackler/rust-openssl#1839

In https://github.com/rust-lang/rustup/actions/runs/4398020553/jobs/7701559253 (which will get deleted at some point) we see

install libcrypto.a -> /checkout/target/x86_64-unknown-illumos/release/build/openssl-sys-6ea040a0afa3c9d0/out/openssl-build/install/lib/libcrypto.a
  Makefile:320: recipe for target 'install_dev' failed

  --- stderr
  crypto/init.c: In function 'OPENSSL_atexit':
  crypto/init.c:763:11: warning: variable 'handlersym' set but not used [-Wunused-but-set-variable]
           } handlersym;
             ^~~~~~~~~~
  x86_64-illumos-ar: creating apps/libapps.a
  /bin/sh: 1: granlib: not found
  x86_64-illumos-ar: creating libssl.a
  /bin/sh: 1: granlib: not found
  x86_64-illumos-ar: creating libcrypto.a
  /bin/sh: 1: granlib: not found
  /bin/sh: 5: granlib: not found
  make: *** [install_dev] Error 127
  thread 'main' panicked at '


  Error installing OpenSSL:
      Command: cd "/checkout/target/x86_64-unknown-illumos/release/build/openssl-sys-6ea040a0afa3c9d0/out/openssl-build/build/src" && "make" "install_dev"
      Exit status: exit status: 2


      ', /cargo/registry/src/github.com-1ecc6299db9ec823/openssl-src-111.25.1+1.1.1t/src/lib.rs:509:13
  stack backtrace:
     0: rust_begin_unwind
               at /rustc/2c8cc343237b8f7d5a3c3703e3a87f2eb2c54a74/library/std/src/panicking.rs:575:5
     1: core::panicking::panic_fmt
               at /rustc/2c8cc343237b8f7d5a3c3703e3a87f2eb2c54a74/library/core/src/panicking.rs:64:14
     2: openssl_src::Build::run_command
     3: openssl_src::Build::build
     4: build_script_main::find_vendored::get_openssl
     5: build_script_main::find_openssl
     6: build_script_main::main
     7: core::ops::function::FnOnce::call_once
  note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.
warning: build failed, waiting for other jobs to finish...
Error: Process completed with exit code 101.

In rustup, we fetch the docker from rust CI cache. The dockerfile for illumos job from https://github.com/rust-lang/rust/blob/master/src/ci/docker/host-x86_64/dist-x86_64-illumos/Dockerfile.

We use it in https://github.com/rust-lang/rustup/blob/master/ci/docker/x86_64-unknown-illumos/Dockerfile

FROM rust-x86_64-unknown-illumos

ENV \
    AR_x86_64_unknown_illumos=x86_64-illumos-ar \
    CC_x86_64_unknown_illumos=x86_64-illumos-gcc \
    CXX_x86_64_unknown_illumos=x86_64-illumos-g++ \
    CARGO_TARGET_X86_64_UNKNOWN_ILLUMOS_LINKER=x86_64-illumos-gcc

It seems we already set the AR environment. But it didn't work.

[jonhoo]

To quote myself from one of those issues:

Oh now that's interesting. The way that's supposed to get picked up is:

1. get_base_archiver_variant calls env_tool
2. env_tool calls get_var
3. get_var checks AR_{target}

Clearly something in that path doesn't work, but it's hard to tell exactly what without access to an illumos system. Any chance you could try adding some debug prints to the above and run the CI to see where the envvar does/does not get picked up?