Use target libraries instead of host libraries. Fixes #11243

src/librustpkg/context.rs

@@ -163,7 +163,8 @@ pub fn add_library_path(&mut self, p: Path) {
 pub fn in_target(sysroot: &Path) -> bool {
     debug!("Checking whether {} is in target", sysroot.display());
     let mut p = sysroot.dir_path();
-    p.set_filename(rustlibdir());
+    p.pop();
+    p.push(rustlibdir());
     p.is_dir()
 }
 

src/librustpkg/path_util.rs

@@ -17,7 +17,7 @@
 pub use version::{Version, ExactRevision, NoVersion, split_version, split_version_general,
     try_parsing_version};
 pub use rustc::metadata::filesearch::rust_path;
-use rustc::metadata::filesearch::libdir;
+use rustc::metadata::filesearch::{libdir, relative_target_lib_path};
 use rustc::driver::driver::host_triple;
 
 use std::libc;
@@ -213,10 +213,9 @@ pub fn library_in_workspace(path: &Path, short_name: &str, where: Target,
     library_in(short_name, version, &dir_to_search)
 }
 
-// rustc doesn't use target-specific subdirectories
 pub fn system_library(sysroot: &Path, crate_id: &str) -> Option<Path> {
     let (lib_name, version) = split_crate_id(crate_id);
-    library_in(lib_name, &version, &sysroot.join(libdir()))
+    library_in(lib_name, &version, &sysroot.join(relative_target_lib_path(host_triple())))
 }
 
 fn library_in(short_name: &str, version: &Version, dir_to_search: &Path) -> Option<Path> {

src/librustpkg/util.rs

@@ -459,7 +459,7 @@ fn visit_view_item(&mut self, vi: &ast::ViewItem, env: ()) {
                 };
                 debug!("Finding and installing... {}", lib_name);
                 // Check standard Rust library path first
-                let whatever = system_library(&self.context.sysroot(), lib_name);
+                let whatever = system_library(&self.context.sysroot_to_use(), lib_name);
                 debug!("system library returned {:?}", whatever);
                 match whatever {
                     Some(ref installed_path) => {