Lets see what's going on

.github/workflows/rust.yml

@@ -8,6 +8,7 @@ on:
 
 env:
   CARGO_TERM_COLOR: always
+  RUST_BACKTRACE: 1
 
 jobs:
   build:

build.rs

@@ -21,6 +21,11 @@ pub fn link_rustc_lib() {
     let rustup_lib = [&rustup_home, "toolchains", &rustup_tc, "lib"]
         .into_iter()
         .collect::<PathBuf>();
+    eprint!("Found the library files: ");
+    for file in std::fs::read_dir(&rustup_lib).expect("Rustup lib dir does not exist") {
+        eprint!("{}, ", file.unwrap().file_name().to_string_lossy());
+    }
+    eprintln!();
     add_link_path_for_compiler_binaries(rustup_lib.display());
 
     // While we hard-code the above for development purposes, for a release/install we look