diff --git a/config.ts b/config.ts
index f427e20..b885639 100644
--- a/config.ts
+++ b/config.ts
@@ -187,6 +187,7 @@ export function actionHandler<
         context.config,
         context.ignore ?? [],
         context.allowNodeModules ?? false,
+        context.debug,
       );
       const configContext: ConfigContext = {
         ...getAppFromConfig(config),
@@ -245,11 +246,13 @@ async function readConfig(
   maybeConfigPath: string | undefined,
   ignorePaths: string[],
   allowNodeModules: boolean,
+  debug: boolean,
 ): Promise<Config> {
   const config = resolve_config(
     resolve(maybeConfigPath || rootPath),
     ignorePaths,
     allowNodeModules,
+    debug,
   );
 
   if (config.path) {
diff --git a/rs_lib/src/lib.rs b/rs_lib/src/lib.rs
index 642ff89..71ebd90 100644
--- a/rs_lib/src/lib.rs
+++ b/rs_lib/src/lib.rs
@@ -10,6 +10,23 @@ use sys_traits::FsMetadata;
 use url::Url;
 use wasm_bindgen::prelude::*;
 
+#[cfg(target_arch = "wasm32")]
+#[wasm_bindgen]
+extern "C" {
+  #[wasm_bindgen(js_namespace = console, js_name = log)]
+  fn console_log(s: &str);
+}
+
+#[cfg(target_arch = "wasm32")]
+fn debug_log(debug: bool, msg: &str) {
+  if debug {
+    console_log(&format!("[rs_lib] {}", msg));
+  }
+}
+
+#[cfg(not(target_arch = "wasm32"))]
+fn debug_log(_debug: bool, _msg: &str) {}
+
 #[derive(Serialize)]
 pub struct ConfigLookup {
   pub path: Option<String>,
@@ -21,9 +38,10 @@ pub fn resolve_config(
   root_path: String,
   ignore_paths: Vec<String>,
   allow_node_modules: bool,
+  debug: bool,
 ) -> Result<JsValue, JsValue> {
   let result =
-    inner_resolve_config(root_path, ignore_paths, allow_node_modules);
+    inner_resolve_config(root_path, ignore_paths, allow_node_modules, debug);
   result
     .map_err(|err| create_js_error(&err))
     .map(|val| serde_wasm_bindgen::to_value(&val).unwrap())
@@ -33,18 +51,30 @@ fn inner_resolve_config(
   root_path: String,
   ignore_paths: Vec<String>,
   allow_node_modules: bool,
+  debug: bool,
 ) -> Result<ConfigLookup, anyhow::Error> {
+  debug_log(
+    debug,
+    &format!(
+      "resolve_config(root_path={:?}, ignore_paths={:?}, allow_node_modules={})",
+      root_path, ignore_paths, allow_node_modules
+    ),
+  );
+
   let real_sys = sys_traits::impls::RealSys;
   let root_path = resolve_absolute_path(root_path)?;
+  debug_log(debug, &format!("resolved absolute root_path={:?}", root_path));
 
   // When --config points to a file (not a directory), use ConfigFile
   // discovery so non-standard filenames like deno-staging.json work.
   let is_config_file = real_sys.fs_is_file(&root_path).unwrap_or(false);
+  debug_log(debug, &format!("is_config_file={}", is_config_file));
   let dir_path = if is_config_file {
     root_path.parent().unwrap().to_path_buf()
   } else {
     root_path.clone()
   };
+  debug_log(debug, &format!("dir_path={:?}", dir_path));
 
   let dir_paths = [dir_path.clone()];
   let discover_start = if is_config_file {
@@ -65,10 +95,31 @@ fn inner_resolve_config(
       maybe_vendor_override: None,
     },
   )?;
+  debug_log(
+    debug,
+    &format!(
+      "workspace discovered: member_deno_json={:?}, root_deno_json={:?}, members={:?}",
+      workspace_dir.member_deno_json().map(|c| c.specifier.to_string()),
+      workspace_dir
+        .workspace
+        .root_deno_json()
+        .map(|c| c.specifier.to_string()),
+      workspace_dir
+        .workspace
+        .config_folders()
+        .keys()
+        .map(|u| u.to_string())
+        .collect::<Vec<_>>(),
+    ),
+  );
 
   let mut pattern = FilePatterns::new_with_base(dir_path.clone());
 
   if !ignore_paths.is_empty() {
+    debug_log(
+      debug,
+      &format!("applying ignore_paths={:?}", ignore_paths),
+    );
     let exclude = PathOrPatternSet::from_exclude_relative_path_or_patterns(
       &dir_path,
       &ignore_paths,
@@ -79,6 +130,13 @@ fn inner_resolve_config(
   }
 
   if let Some(config) = workspace_dir.to_deploy_config(pattern)? {
+    debug_log(
+      debug,
+      &format!(
+        "deploy config: include={:?}, exclude={:?}",
+        config.files.include, config.files.exclude,
+      ),
+    );
     let specifier = workspace_dir
       .member_deno_json()
       .filter(|config| config.to_deploy_config().is_ok())
@@ -91,8 +149,9 @@ fn inner_resolve_config(
       .expect(
         "workspace_dir.to_deploy_config should have resolved a specifier",
       );
+    debug_log(debug, &format!("deploy config specifier={}", specifier));
     let files =
-      collect_files(&real_sys, dir_path, config.files, allow_node_modules);
+      collect_files(&real_sys, dir_path, config.files, allow_node_modules, debug);
     Ok(ConfigLookup {
       path: Some(specifier),
       files,
@@ -105,15 +164,21 @@ fn inner_resolve_config(
         workspace_dir.workspace.root_deno_json()
           .map(|member| member.specifier.to_string())
       });
-    Ok(ConfigLookup {
-      path,
-      files: collect_files(
-        &real_sys,
-        dir_path.clone(),
-        FilePatterns::new_with_base(dir_path),
-        allow_node_modules,
+    debug_log(
+      debug,
+      &format!(
+        "no deploy config found; fallback config path={:?}",
+        path,
       ),
-    })
+    );
+    let files = collect_files(
+      &real_sys,
+      dir_path.clone(),
+      FilePatterns::new_with_base(dir_path),
+      allow_node_modules,
+      debug,
+    );
+    Ok(ConfigLookup { path, files })
   }
 }
 
@@ -122,21 +187,58 @@ fn collect_files(
   root_path: PathBuf,
   files: FilePatterns,
   allow_node_modules: bool,
+  debug: bool,
 ) -> Vec<String> {
-  let mut collector =
-    FileCollector::new(|entry| entry.path.starts_with(&root_path))
-      .ignore_git_folder()
-      .use_gitignore();
+  let filter_root = root_path.clone();
+  let mut collector = FileCollector::new(move |entry| {
+    let kept = entry.path.starts_with(&filter_root);
+    debug_log(
+      debug,
+      &format!(
+        "walk entry path={:?} is_dir={} kept={} (root={:?})",
+        entry.path,
+        entry.metadata.file_type().is_dir(),
+        kept,
+        filter_root,
+      ),
+    );
+    kept
+  })
+  .ignore_git_folder()
+  .use_gitignore();
 
   if !allow_node_modules {
     collector = collector.ignore_node_modules();
   }
 
-  collector
+  debug_log(
+    debug,
+    &format!(
+      "collector config: ignore_git_folder=true, use_gitignore=true, ignore_node_modules={}",
+      !allow_node_modules,
+    ),
+  );
+
+  let collected: Vec<String> = collector
     .collect_file_patterns(real_sys, &files)
     .into_iter()
     .map(|path| path.to_string_lossy().to_string())
-    .collect::<Vec<String>>()
+    .collect();
+
+  debug_log(
+    debug,
+    &format!(
+      "collect_files(root_path={:?}, allow_node_modules={}, include={:?}, exclude={:?}) -> {} file(s): {:?}",
+      root_path,
+      allow_node_modules,
+      files.include,
+      files.exclude,
+      collected.len(),
+      collected,
+    ),
+  );
+
+  collected
 }
 
 fn resolve_absolute_path(path: String) -> Result<PathBuf, anyhow::Error> {
@@ -195,6 +297,7 @@ mod tests {
       root.to_string_lossy().into_owned(),
       Vec::new(),
       false,
+      false,
     )
     .unwrap();