Add library path for real rustdoc with RUSTDOC_LIBDIR environment variable.

Author: o01eg

src/bootstrap/bin/rustdoc.rs

@@ -23,7 +23,7 @@ use std::path::PathBuf;
 fn main() {
     let args = env::args_os().skip(1).collect::<Vec<_>>();
     let rustdoc = env::var_os("RUSTDOC_REAL").expect("RUSTDOC_REAL was not set");
-    let libdir = env::var_os("RUSTC_LIBDIR").expect("RUSTC_LIBDIR was not set");
+    let libdir = env::var_os("RUSTDOC_LIBDIR").expect("RUSTDOC_LIBDIR was not set");
     let stage = env::var("RUSTC_STAGE").expect("RUSTC_STAGE was not set");
     let sysroot = env::var_os("RUSTC_SYSROOT").expect("RUSTC_SYSROOT was not set");
 

src/bootstrap/builder.rs

@@ -416,7 +416,7 @@ impl<'a> Builder<'a> {
         let compiler = self.compiler(self.top_stage, host);
         cmd.env("RUSTC_STAGE", compiler.stage.to_string())
            .env("RUSTC_SYSROOT", self.sysroot(compiler))
-           .env("RUSTC_LIBDIR", self.sysroot_libdir(compiler, self.build.build))
+           .env("RUSTDOC_LIBDIR", self.sysroot_libdir(compiler, self.build.build))
            .env("CFG_RELEASE_CHANNEL", &self.build.config.channel)
            .env("RUSTDOC_REAL", self.rustdoc(host))
            .env("RUSTDOC_CRATE_VERSION", self.build.rust_version())
@@ -496,6 +496,9 @@ impl<'a> Builder<'a> {
         if let Some(target_linker) = self.build.linker(target) {
             cargo.env("RUSTC_TARGET_LINKER", target_linker);
         }
+        if cmd != "build" {
+            cargo.env("RUSTDOC_LIBDIR", self.rustc_libdir(self.compiler(2, self.build.build)));
+        }
 
         if mode != Mode::Tool {
             // Tools don't get debuginfo right now, e.g. cargo and rls don't