Error when trying to build a Rust project on OpenBSD

[lcheylus]

I'm trying to use sccache to build a Rust project on OpenBSD version 7.5 (release April 2024) on amd64.

• sccache installed via OpenBSD port (pkg_add sccache) => version 0.7.7

  $ sccache -V
  sccache 0.7.7

• Rust version 1.76.0 (installed via OpenBSD ports)

  $ rustc -vV
  rustc 1.76.0 (07dca489a 2024-02-04) (built from a source tarball)
  binary: rustc
  commit-hash: 07dca489ac2d933c78d3c5158e3f43beefeb02ce
  commit-date: 2024-02-04
  host: x86_64-unknown-openbsd
  release: 1.76.0
  LLVM version: 16.0.6

Error when trying to build a Rust project with cargo and sccache (local storage):

$ export RUSTC_WRAPPER=sccache
$ cargo build
error: failed to run `rustc` to learn about target-specific information

Caused by:
  process didn't exit successfully: `sccache rustc - --crate-name ___ --print=file-names --cfg tokio_unstable --crate-type bin --crate-type rlib --crate-type dylib --crate-type cdylib --crate-type staticlib --crate-type proc-macro --print=sysroot --print=split-debuginfo --print=crate-name --print=cfg` (exit status: 2)
  --- stderr
  sccache: error: no current exe available (short)

I was not able to find a similar issue or this error message in code (no current exe available (short)).

Have you some clue to debug this error?

[lcheylus]

Same error on OpenBSD current (amd64) with Rust 1.78.0 and sccache 0.8.0

$ rustc -vV
rustc 1.78.0 (15adfb9cd 2024-04-28) (built from a source tarball)
binary: rustc
commit-hash: 15adfb9cd5b029268e1470a41391d91859b0a1f8
commit-date: 2024-04-28
host: x86_64-unknown-openbsd
release: 1.78.0
LLVM version: 16.0.6

$ sccache -V
sccache 0.8.0

$ cd <my Rust project>
$ export RUSTC_WRAPPER=sccache
$ cargo build -v
error: failed to run `rustc` to learn about target-specific information

Caused by:
  process didn't exit successfully: `sccache rustc - --crate-name ___ --print=file-names --crate-type bin --crate-type rlib --crate-type dylib --crate-type cdylib --crate-type staticlib --crate-type proc-macro --print=sysroot --print=split-debuginfo --print=crate-name --print=cfg` (exit status: 2)
  --- stderr
  sccache: error: no current exe available (short)

[sylvestre]

Salut Laurent!

This error ringed a bell! I improved the error message when calling current_exe on Linux for this 7 years ago :| https://github.com/rust-lang/rust/commit/1b6a182cf1e400b63ae8692e3183beabe541ea6c

On Linux, it means that chroot isn't correctly set up. (/proc not mounted)

On openbsd, it seems that the libc call is failing: https://github.com/rust-lang/rust/blob/2a2c29aafa50bf6fe53d66b32070eba59f860ac3/library/std/src/sys/pal/unix/os.rs#L385

so, afaik, it isn't a sccache error.

[lcheylus]

Salut Sylvestre :)

Thanks for your infos. Strange error when calling rustc from sccache, I have no issue when I call it directly.

$ rustc -V
rustc 1.78.0 (15adfb9cd 2024-04-28) (built from a source tarball)

$ sccache rustc -V
sccache: error: no current exe available (short)