fix: make std_features CI rustc incompatible

Author: shrirambalaji

src/bootstrap/src/core/build_steps/compile.rs

@@ -553,9 +553,7 @@ pub fn std_cargo(builder: &Builder<'_>, target: TargetSelection, stage: u32, car
             .arg("--features")
             .arg(features);
     } else {
-        let builder_std_features = format!(" {}", &builder.std_features(target));
-
-        features += &builder_std_features;
+        features += &builder.std_features(target);
         features.push_str(compiler_builtins_c_feature);
 
         cargo

src/bootstrap/src/core/config/config.rs

@@ -2998,6 +2998,7 @@ fn check_incompatible_options_for_ci_rustc(
         description,
         incremental,
         default_linker,
+        std_features,
 
         // Rest of the options can simply be ignored.
         debug: _,
@@ -3037,7 +3038,6 @@ fn check_incompatible_options_for_ci_rustc(
         download_rustc: _,
         validate_mir_opts: _,
         frame_pointers: _,
-        std_features: _,
     } = ci_rust_config;
 
     // There are two kinds of checks for CI rustc incompatible options:
@@ -3060,6 +3060,7 @@ fn check_incompatible_options_for_ci_rustc(
     err!(current_rust_config.default_linker, default_linker);
     err!(current_rust_config.stack_protector, stack_protector);
     err!(current_rust_config.lto, lto);
+    err!(current_rust_config.std_features, std_features);
 
     warn!(current_rust_config.channel, channel);
     warn!(current_rust_config.description, description);

src/bootstrap/src/lib.rs

@@ -661,7 +661,8 @@ impl Build {
         &self.config.rust_info
     }
 
-    /// Gets the space-separated set of activated features for the standard ibrary. This can be configured with the `std-features` key in config.toml.
+    /// Gets the space-separated set of activated features for the standard library.
+    /// This can be configured with the `std-features` key in config.toml.
     fn std_features(&self, target: TargetSelection) -> String {
         let mut features: BTreeSet<&str> =
             self.config.rust_std_features.iter().map(|s| s.as_str()).collect();