3 files changed, 31 insertions, 9 deletions
diff --git a/src/bootstrap/bootstrap.py b/src/bootstrap/bootstrap.py
index fea194a80ef..28d96cb1cfe 100644
--- a/src/bootstrap/bootstrap.py
+++ b/src/bootstrap/bootstrap.py
@@ -917,8 +917,24 @@ class RustBuild(object):
             if toml_val is not None:
                 env["{}_{}".format(var_name, host_triple_sanitized)] = toml_val
 
-        # preserve existing RUSTFLAGS
-        env.setdefault("RUSTFLAGS", "")
+        # In src/etc/rust_analyzer_settings.json, we configure rust-analyzer to
+        # pass RUSTC_BOOTSTRAP=1 to all cargo invocations because the standard
+        # library uses unstable Cargo features. Without RUSTC_BOOTSTRAP,
+        # rust-analyzer would fail to fetch workspace layout when the system's
+        # default toolchain is not nightly.
+        #
+        # But that setting has the collateral effect of rust-analyzer also
+        # passing RUSTC_BOOTSTRAP=1 to all x.py invocations too (the various overrideCommand).
+        # For compiling bootstrap that can cause spurious rebuilding of bootstrap when
+        # rust-analyzer x.py invocations are interleaved with handwritten ones on the
+        # command line.
+        #
+        # Set RUSTC_BOOTSTRAP=1 consistently.
+        env["RUSTC_BOOTSTRAP"] = "1"
+
+        default_rustflags = "" if env.get("RUSTFLAGS_BOOTSTRAP", "") else "-Zallow-features="
+
+        env.setdefault("RUSTFLAGS", default_rustflags)
 
         target_features = []
         if self.get_toml("crt-static", build_section) == "true":
diff --git a/src/bootstrap/src/core/build_steps/setup.rs b/src/bootstrap/src/core/build_steps/setup.rs
index 9c897ae1bb7..dd9c68aba7f 100644
--- a/src/bootstrap/src/core/build_steps/setup.rs
+++ b/src/bootstrap/src/core/build_steps/setup.rs
@@ -37,6 +37,7 @@ static SETTINGS_HASHES: &[&str] = &[
     "3468fea433c25fff60be6b71e8a215a732a7b1268b6a83bf10d024344e140541",
     "47d227f424bf889b0d899b9cc992d5695e1b78c406e183cd78eafefbe5488923",
     "b526bd58d0262dd4dda2bff5bc5515b705fb668a46235ace3e057f807963a11a",
+    "828666b021d837a33e78d870b56d34c88a5e2c85de58b693607ec574f0c27000",
 ];
 static RUST_ANALYZER_SETTINGS: &str = include_str!("../../../../etc/rust_analyzer_settings.json");
 
diff --git a/src/bootstrap/src/core/builder.rs b/src/bootstrap/src/core/builder.rs
index 4e20babc55a..3770d0687b2 100644
--- a/src/bootstrap/src/core/builder.rs
+++ b/src/bootstrap/src/core/builder.rs
@@ -1799,15 +1799,20 @@ impl<'a> Builder<'a> {
         }
 
         if self.config.rust_remap_debuginfo {
-            // FIXME: handle vendored sources
-            let registry_src = t!(home::cargo_home()).join("registry").join("src");
             let mut env_var = OsString::new();
-            for entry in t!(std::fs::read_dir(registry_src)) {
-                if !env_var.is_empty() {
-                    env_var.push("\t");
-                }
-                env_var.push(t!(entry).path());
+            if self.config.vendor {
+                let vendor = self.build.src.join("vendor");
+                env_var.push(vendor);
                 env_var.push("=/rust/deps");
+            } else {
+                let registry_src = t!(home::cargo_home()).join("registry").join("src");
+                for entry in t!(std::fs::read_dir(registry_src)) {
+                    if !env_var.is_empty() {
+                        env_var.push("\t");
+                    }
+                    env_var.push(t!(entry).path());
+                    env_var.push("=/rust/deps");
+                }
             }
             cargo.env("RUSTC_CARGO_REGISTRY_SRC_TO_REMAP", env_var);
         }