Explicitly clear hidden attribute for final files on MacOS

Otherwise sometimes files will keep their hidden attribute after being
moved from a ".tmp" name to their final destination.

CHANGELOG.md

@@ -35,6 +35,7 @@ ambiguous situations.
 - Crawling of nested courses
 - Downloading of links with no target URL
 - Handle row flex on description pages
+- Files sometimes appearing as hidden on MacOS
 
 ## 3.6.0 - 2024-10-23
 

PFERD/output_dir.py

@@ -425,6 +425,17 @@ async def download(
         return FileSinkToken(self, remote_path, path, local_path, heuristics, on_conflict)
 
     def _update_metadata(self, info: DownloadInfo) -> None:
+        # Clear hidden attribute on MacOS
+        # chflags is only available on some unixes
+        if hasattr(os, "chflags"):
+            import stat
+            stat_result = os.stat(info.local_path)
+            # Not present on all unixes
+            if hasattr(stat_result, "st_flags"):
+                flags = getattr(stat_result, "st_flags")
+                flags &= ~stat.UF_HIDDEN
+                os.chflags(info.local_path, flags)
+
         if mtime := info.heuristics.mtime:
             mtimestamp = mtime.timestamp()
             os.utime(info.local_path, times=(mtimestamp, mtimestamp))