Add track_caller to builder.msg

this makes the panics on nested GHA groups more useful

src/bootstrap/lib.rs

@@ -1000,6 +1000,7 @@ impl Build {
     }
 
     #[must_use = "Groups should not be dropped until the Step finishes running"]
+    #[track_caller]
     fn msg_check(
         &self,
         what: impl Display,
@@ -1009,6 +1010,7 @@ impl Build {
     }
 
     #[must_use = "Groups should not be dropped until the Step finishes running"]
+    #[track_caller]
     fn msg_doc(
         &self,
         compiler: Compiler,
@@ -1019,6 +1021,7 @@ impl Build {
     }
 
     #[must_use = "Groups should not be dropped until the Step finishes running"]
+    #[track_caller]
     fn msg_build(
         &self,
         compiler: Compiler,
@@ -1032,6 +1035,7 @@ impl Build {
     ///
     /// [`Step`]: crate::builder::Step
     #[must_use = "Groups should not be dropped until the Step finishes running"]
+    #[track_caller]
     fn msg(
         &self,
         action: impl Into<Kind>,
@@ -1059,6 +1063,7 @@ impl Build {
     ///
     /// [`Step`]: crate::builder::Step
     #[must_use = "Groups should not be dropped until the Step finishes running"]
+    #[track_caller]
     fn msg_unstaged(
         &self,
         action: impl Into<Kind>,
@@ -1071,6 +1076,7 @@ impl Build {
     }
 
     #[must_use = "Groups should not be dropped until the Step finishes running"]
+    #[track_caller]
     fn msg_sysroot_tool(
         &self,
         action: impl Into<Kind>,
@@ -1089,6 +1095,7 @@ impl Build {
         self.group(&msg)
     }
 
+    #[track_caller]
     fn group(&self, msg: &str) -> Option<gha::Group> {
         match self.config.dry_run {
             DryRun::SelfCheck => None,

src/bootstrap/tool.rs

@@ -34,6 +34,7 @@ struct ToolBuild {
 }
 
 impl Builder<'_> {
+    #[track_caller]
     fn msg_tool(
         &self,
         mode: Mode,

src/tools/build_helper/src/ci.rs

@@ -43,6 +43,7 @@ pub mod gha {
     /// All github actions log messages from this call to the Drop of the return value
     /// will be grouped and hidden by default in logs. Note that nesting these does
     /// not really work.
+    #[track_caller]
     pub fn group(name: impl std::fmt::Display) -> Group {
         if std::env::var_os("GITHUB_ACTIONS").is_some() {
             eprintln!("::group::{name}");