3 files changed, 23 insertions, 0 deletions
diff --git a/src/makefile/input.rs b/src/makefile/input.rs
index d6f6254..6ee5392 100644
--- a/src/makefile/input.rs
+++ b/src/makefile/input.rs
@@ -413,6 +413,11 @@ impl<'a, 'parent, R: BufRead> MakefileReader<'a, 'parent, R> {
                 inference_match.name("s2").unwrap().as_str().to_owned(),
                 commands,
             );
+            log::trace!(
+                "suffix-based inference rule defined by {:?} - {:?}",
+                &inference_match,
+                &new_rule,
+            );
 
             self.inference_rules.retain(|existing_rule| {
                 (&existing_rule.prerequisites, &existing_rule.products)
diff --git a/src/makefile/mod.rs b/src/makefile/mod.rs
index e13ecff..0f8cfd2 100644
--- a/src/makefile/mod.rs
+++ b/src/makefile/mod.rs
@@ -153,9 +153,16 @@ impl<'a> Makefile<'a> {
                     .chain(self.builtin_inference_rules.iter())
                     .filter(|rule| rule.matches(name).unwrap_or(false));
                 for rule in inference_rule_candidates {
+                    log::trace!(
+                        "{:>58} considering rule to build {:?} from {:?}",
+                        name,
+                        &rule.products,
+                        &rule.prerequisites
+                    );
                     // whose prerequisite file ($*.s2) exists.
                     let prereq_paths = rule
                         .prereqs(name)?
+                        .inspect(|x| log::trace!("{:>58} prereq {}", name, x))
                         .map(|prereq_path_name| {
                             if name == prereq_path_name {
                                 // we can't build this based on itself! fuck outta here
diff --git a/src/makefile/target.rs b/src/makefile/target.rs
index ad46884..1c382d0 100644
--- a/src/makefile/target.rs
+++ b/src/makefile/target.rs
@@ -53,6 +53,12 @@ impl Target {
                 .and_then(|t| self.newer_than(&t.borrow()))
                 .unwrap_or(false)
         });
+        log::trace!(
+            "{:>50} exists: {}, newer than dependencies: {}",
+            self.name,
+            exists,
+            newer_than_all_dependencies
+        );
         exists && newer_than_all_dependencies
     }
 
@@ -62,6 +68,10 @@ impl Target {
                 .wrap_err_with(|| format!("as a dependency for target {}", self.name))?;
         }
         if !self.is_up_to_date(file) {
+            log::debug!("rebuilding {}...", self.name);
+            if self.commands.is_empty() {
+                log::warn!("no commands found to rebuild {}", self.name);
+            }
             self.execute_commands(file)
                 .wrap_err_with(|| format!("while updating target {}", self.name))?;
         }
@@ -72,6 +82,7 @@ impl Target {
 
     fn execute_commands(&self, file: &Makefile) -> Result<()> {
         for command in &self.commands {
+            log::trace!("  executing {}", command);
             command.execute(file, self)?;
         }