Add logic to override profile for non git sources

Author: tanvincible

src/bootstrap/bootstrap.py

@@ -1268,6 +1268,11 @@ def bootstrap(args):
         config_toml = ""
 
     profile = RustBuild.get_toml_static(config_toml, "profile")
+    is_non_git_source = not os.path.exists(os.path.join(rust_root, ".git"))
+
+    if profile is None and is_non_git_source:
+        profile = "dist"
+
     if profile is not None:
         # Allows creating alias for profile names, allowing
         # profiles to be renamed while maintaining back compatibility

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

@@ -2926,10 +2926,8 @@ impl Config {
         let if_unchanged = || {
             if self.rust_info.is_from_tarball() {
                 // Git is needed for running "if-unchanged" logic.
-                println!(
-                    "WARNING: 'if-unchanged' has no effect on tarball sources; ignoring `download-ci-llvm`."
-                );
-                return false;
+                println!("ERROR: 'if-unchanged' is only compatible with Git managed sources.");
+                crate::exit!(1);
             }
 
             // Fetching the LLVM submodule is unnecessary for self-tests.