Include error message with error status

blender_asset_tracer/pack/__init__.py

@@ -192,15 +192,17 @@ class Packer:
         """Raises an Aborted exception when abort() was called."""
 
         with self._abort_lock:
+            reason = ''
             if self._file_transferer is not None and self._file_transferer.has_error:
                 log.error('A transfer error occurred')
+                reason = self._file_transferer.error_message()
             elif not self._aborted.is_set():
                 return
 
             log.warning('Aborting')
             self._tscb.flush()
             self._progress_cb.pack_aborted()
-            raise Aborted()
+            raise Aborted(reason)
 
     def exclude(self, *globs: str):
         """Register glob-compatible patterns of files that should be ignored.

blender_asset_tracer/pack/filesystem.py

@@ -58,13 +58,14 @@ class FileCopier(transfer.FileTransferer):
     def run(self) -> None:
 
         pool = multiprocessing.pool.ThreadPool(processes=self.transfer_threads)
-
+        dst = pathlib.Path()
         for src, pure_dst, act in self.iter_queue():
             try:
-                if self._error.is_set() or self._abort.is_set():
+                dst = pathlib.Path(pure_dst)
+
+                if self.has_error or self._abort.is_set():
                     raise AbortTransfer()
 
-                dst = pathlib.Path(pure_dst)
                 if self._skip_file(src, dst, act):
                     continue
 
@@ -82,8 +83,9 @@ class FileCopier(transfer.FileTransferer):
                 if self._abort.is_set():
                     log.debug('Error transferring %s to %s: %s', src, dst, ex)
                 else:
-                    log.exception('Error transferring %s to %s', src, dst)
+                    msg = 'Error transferring %s to %s' % (src, dst)
-                    self._error.set()
+                    log.exception(msg)
+                    self.error_set(msg)
                 # Put the files to copy back into the queue, and abort. This allows
                 # the main thread to inspect the queue and see which files were not
                 # copied. The one we just failed (due to this exception) should also
@@ -106,7 +108,7 @@ class FileCopier(transfer.FileTransferer):
         try:
             tfunc = self.transfer_funcs[src.is_dir(), act]
 
-            if self._error.is_set() or self._abort.is_set():
+            if self.has_error or self._abort.is_set():
                 raise AbortTransfer()
 
             log.info('%s %s -> %s', act.name, src, dst)
@@ -121,8 +123,9 @@ class FileCopier(transfer.FileTransferer):
             if self._abort.is_set():
                 log.debug('Error transferring %s to %s: %s', src, dst, ex)
             else:
-                log.exception('Error transferring %s to %s', src, dst)
+                msg = 'Error transferring %s to %s' % (src, dst)
-                self._error.set()
+                log.exception(msg)
+                self.error_set(msg)
             # Put the files to copy back into the queue, and abort. This allows
             # the main thread to inspect the queue and see which files were not
             # copied. The one we just failed (due to this exception) should also
@@ -164,7 +167,7 @@ class FileCopier(transfer.FileTransferer):
     def copyfile(self, srcpath: pathlib.Path, dstpath: pathlib.Path):
         """Copy a file, skipping when it already exists."""
 
-        if self._abort.is_set() or self._error.is_set():
+        if self._abort.is_set() or self.has_error:
             return
 
         if (srcpath, dstpath) in self.already_copied:
@@ -204,13 +207,13 @@ class FileCopier(transfer.FileTransferer):
             log.debug('SKIP %s; already copied', src)
             return
 
-        if self._error.is_set() or self._abort.is_set():
+        if self.has_error or self._abort.is_set():
             raise AbortTransfer()
 
         dst.mkdir(parents=True, exist_ok=True)
         errors = []  # type: typing.List[typing.Tuple[pathlib.Path, pathlib.Path, str]]
         for srcpath in src.iterdir():
-            if self._error.is_set() or self._abort.is_set():
+            if self.has_error or self._abort.is_set():
                 raise AbortTransfer()
 
             dstpath = dst / srcpath.name

blender_asset_tracer/pack/transfer.py

@@ -70,7 +70,10 @@ class FileTransferer(threading.Thread, metaclass=abc.ABCMeta):
         self.queue = queue.PriorityQueue(maxsize=100)  # type: queue.PriorityQueue[QueueItem]
         self.done = threading.Event()
         self._abort = threading.Event()  # Indicates user-requested abort
-        self._error = threading.Event()  # Indicates abort due to some error
+
+        self.__error_mutex = threading.Lock()
+        self.__error = threading.Event()  # Indicates abort due to some error
+        self.__error_message = ''
 
         # Instantiate a dummy progress callback so that we can call it
         # without checking for None all the time.
@@ -86,7 +89,7 @@ class FileTransferer(threading.Thread, metaclass=abc.ABCMeta):
         """Queue a copy action from 'src' to 'dst'."""
         assert not self.done.is_set(), 'Queueing not allowed after done_and_join() was called'
         assert not self._abort.is_set(), 'Queueing not allowed after abort_and_join() was called'
-        if self._error.is_set():
+        if self.__error.is_set():
             return
         self.queue.put((src, dst, Action.COPY))
         self.total_queued_bytes += src.stat().st_size
@@ -95,7 +98,7 @@ class FileTransferer(threading.Thread, metaclass=abc.ABCMeta):
         """Queue a move action from 'src' to 'dst'."""
         assert not self.done.is_set(), 'Queueing not allowed after done_and_join() was called'
         assert not self._abort.is_set(), 'Queueing not allowed after abort_and_join() was called'
-        if self._error.is_set():
+        if self.__error.is_set():
             return
         self.queue.put((src, dst, Action.MOVE))
         self.total_queued_bytes += src.stat().st_size
@@ -156,7 +159,7 @@ class FileTransferer(threading.Thread, metaclass=abc.ABCMeta):
         """Generator, yield queued items until the work is done."""
 
         while True:
-            if self._abort.is_set() or self._error.is_set():
+            if self._abort.is_set() or self.__error.is_set():
                 return
 
             try:
@@ -197,4 +200,22 @@ class FileTransferer(threading.Thread, metaclass=abc.ABCMeta):
 
     @property
     def has_error(self) -> bool:
-        return self._error.is_set()
+        return self.__error.is_set()
+
+    def error_set(self, message: str):
+        """Indicate an error occurred, and provide a message."""
+
+        with self.__error_mutex:
+            # Avoid overwriting previous error messages.
+            if self.__error.is_set():
+                return
+
+            self.__error.set()
+            self.__error_message = message
+
+    def error_message(self) -> str:
+        """Retrieve the error messsage, or an empty string if no error occurred."""
+        with self.__error_mutex:
+            if not self.__error.is_set():
+                return ''
+            return self.__error_message