Provide bootstrap tools with RUSTC in environment

src/bootstrap/test.rs

@@ -1281,6 +1281,8 @@ impl Step for Compiletest {
             cmd.arg("--rustfix-coverage");
         }
 
+        cmd.env("BOOTSTRAP_CARGO", &builder.initial_cargo);
+
         builder.ci_env.force_coloring_in_ci(&mut cmd);
 
         builder.info(&format!(

src/bootstrap/tool.rs

@@ -700,6 +700,10 @@ impl<'a> Builder<'a> {
         }
 
         add_dylib_path(lib_paths, &mut cmd);
+
+        // Provide a RUSTC for this command to use.
+        cmd.env("RUSTC", &self.initial_rustc);
+
         cmd
     }
 }

src/test/run-make/thumb-none-cortex-m/Makefile

@@ -35,4 +35,4 @@ all:
 	# HACK(eddyb) sets `RUSTC_BOOTSTRAP=1` so Cargo can accept nightly features.
 	# These come from the top-level Rust workspace, that this crate is not a
 	# member of, but Cargo tries to load the workspace `Cargo.toml` anyway.
-	cd $(WORK_DIR) && cd $(CRATE) && env RUSTC_BOOTSTRAP=1 $(CARGO) build --target $(TARGET) -v
+	cd $(WORK_DIR) && cd $(CRATE) && env RUSTC_BOOTSTRAP=1 $(BOOTSTRAP_CARGO) build --target $(TARGET) -v

src/test/run-make/thumb-none-qemu/script.sh

@@ -12,8 +12,8 @@ pushd $WORK_DIR
         # These come from the top-level Rust workspace, that this crate is not a
         # member of, but Cargo tries to load the workspace `Cargo.toml` anyway.
         env RUSTC_BOOTSTRAP=1 RUSTFLAGS="-C linker=arm-none-eabi-ld -C link-arg=-Tlink.x" \
-            $CARGO run --target $TARGET           | grep "x = 42"
+            $BOOTSTRAP_CARGO run --target $TARGET           | grep "x = 42"
         env RUSTC_BOOTSTRAP=1 RUSTFLAGS="-C linker=arm-none-eabi-ld -C link-arg=-Tlink.x" \
-            $CARGO run --target $TARGET --release | grep "x = 42"
+            $BOOTSTRAP_CARGO run --target $TARGET --release | grep "x = 42"
     popd
 popd