try debugging proc-macro erro

src/docbuilder/caching.rs

@@ -6,7 +6,8 @@ use std::{
     time::SystemTime,
 };
 use sysinfo::{DiskExt, RefreshKind, System, SystemExt};
-use tracing::{debug, instrument, warn};
+use tracing::{debug, info, instrument, warn};
+use walkdir::WalkDir;
 
 static LAST_ACCESSED_FILE_NAME: &str = "docsrs_last_accessed";
 
@@ -153,6 +154,14 @@ impl ArtifactCache {
         Ok(())
     }
 
+    fn print_directory_contents<P: AsRef<Path>>(path: P) -> Result<()> {
+        info!("directory contents of {}:", path.as_ref().display());
+        for entry in WalkDir::new(path) {
+            info!("\t{}", entry?.path().display());
+        }
+        Ok(())
+    }
+
     /// restore a cached target directory.
     ///
     /// Will just move the cache folder into the rustwide
@@ -181,6 +190,7 @@ impl ArtifactCache {
         fs::create_dir_all(target_dir.parent().unwrap())?;
         fs::rename(cache_dir, target_dir).context("could not move cache directory to target")?;
         self.cleanup(target_dir)?;
+        self.print_directory_contents(target_dir)?;
         Ok(())
     }
 

src/docbuilder/rustwide_builder.rs

@@ -105,6 +105,12 @@ impl RustwideBuilder {
         })
     }
 
+    pub fn init_for_test(context: &dyn Context) -> Result<Self> {
+        let builder = Self::init(context)?;
+        builder.artifact_cache.purge()?;
+        Ok(builder)
+    }
+
     pub fn set_skip_build_if_exists(&mut self, should: bool) {
         self.skip_build_if_exists = should;
     }