Add some traces

Author: Xanewok

src/build/cargo.rs

@@ -171,6 +171,7 @@ fn run_cargo(
     let pkg_names = spec.into_package_id_specs(&ws)?.iter()
         .map(|pkg_spec| pkg_spec.name().to_owned())
         .collect();
+    trace!("Specified packages to be built by Cargo: {:#?}", pkg_names);
 
     // Since Cargo build routine will try to regenerate the unit dep graph,
     // we need to clear the existing dep graph.

src/build/mod.rs

@@ -548,6 +548,8 @@ impl Internals {
             };
             cx.build_plan.prepare_work(&manifest_path, &modified, needs_to_run_cargo)
         };
+        trace!("Specified work: {:?}", work);
+
         match work {
             // Cargo performs the full build and returns
             // appropriate diagnostics/analysis data

src/build/plan.rs

@@ -25,6 +25,7 @@
 //! build scripts).
 
 use std::collections::{HashMap, HashSet};
+use std::ffi::OsStr;
 use std::fmt;
 use std::path::{Path, PathBuf};
 use std::sync::{Arc, Mutex};
@@ -468,7 +469,6 @@ impl PackageMap {
     }
 }
 
-#[derive(Debug)]
 crate struct JobQueue(Vec<ProcessBuilder>);
 
 fn proc_arg<T: AsRef<OsStr>>(prc: &ProcessBuilder, key: T) -> Option<&std::ffi::OsStr> {
@@ -480,6 +480,19 @@ fn proc_arg<T: AsRef<OsStr>>(prc: &ProcessBuilder, key: T) -> Option<&std::ffi::
         .map(|x| x.as_os_str())
 }
 
+impl fmt::Debug for JobQueue {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(f, "JobQueue: [")?;
+        for prog in self.0.iter().rev() {
+            let name = proc_arg(prog, "--crate-name").unwrap();
+            let typ_ = proc_arg(prog, "--crate-type").unwrap_or_else(|| OsStr::new("<unknown>"));
+            write!(f, "{:?} ({:?}), ", name, typ_);
+        }
+        write!(f, "]")?;
+        Ok(())
+    }
+}
+
 impl JobQueue {
     crate fn dequeue(&mut self) -> Option<ProcessBuilder> {
         self.0.pop()