Auto merge of rust-lang#110281 - ozkanonur:multiarch-compatible-sysro…

…ot-finding, r=jackh726

make sysroot finding compatible with multiarch systems

Tested on Debian 11 multiarch, worked just fine.

resolves rust-lang#109994

compiler/rustc_session/src/filesearch.rs

@@ -227,28 +227,29 @@ pub fn get_or_default_sysroot() -> Result<PathBuf, String> {
  ))?;
 
  // if `dir` points target's dir, move up to the sysroot
- if dir.ends_with(crate::config::host_triple()) {
+ let mut sysroot_dir = if dir.ends_with(crate::config::host_triple()) {
  dir.parent() // chop off `$target`
  .and_then(|p| p.parent()) // chop off `rustlib`
- .and_then(|p| {
- // chop off `lib` (this could be also $arch dir if the host sysroot uses a
- // multi-arch layout like Debian or Ubuntu)
- match p.parent() {
- Some(p) => match p.file_name() {
- Some(f) if f == "lib" => p.parent(), // first chop went for $arch, so chop again for `lib`
- _ => Some(p),
- },
- None => None,
- }
- })
+ .and_then(|p| p.parent()) // chop off `lib`
  .map(|s| s.to_owned())
- .ok_or(format!(
- "Could not move 3 levels upper using `parent()` on {}",
- dir.display()
- ))
+ .ok_or_else(|| {
+ format!("Could not move 3 levels upper using `parent()` on {}", dir.display())
+ })?
  } else {
- Ok(dir.to_owned())
+ dir.to_owned()
+ };
+
+ // On multiarch linux systems, there will be multiarch directory named
+ // with the architecture(e.g `x86_64-linux-gnu`) under the `lib` directory.
+ // Which cause us to mistakenly end up in the lib directory instead of the sysroot directory.
+ if sysroot_dir.ends_with("lib") {
+ sysroot_dir =
+ sysroot_dir.parent().map(|real_sysroot| real_sysroot.to_owned()).ok_or_else(
+ || format!("Could not move to parent path of {}", sysroot_dir.display()),
+ )?
  }
+
+ Ok(sysroot_dir)
  }
 
  // Use env::args().next() to get the path of the executable without