RESOLVED #18, Improve error output

UPDATED version to 0.6.5

btrfs_sxbackup/__init__.py

@@ -5,7 +5,7 @@
 # Software Foundation; either version 2 of the License, or (at your option)
 # any later version.
 
-__version__ = '0.6.4'
+__version__ = '0.6.5'
 __author__ = 'Marco Schindler'
 __email__ = 'masc@disappear.de'
 __maintainer__ = 'masc@disappear.de'

btrfs_sxbackup/core.py

@@ -138,6 +138,9 @@ def _log_info(self, msg):
     def _log_warn(self, msg):
         self.__logger.warn(self._format_log_msg(msg))
 
+    def _log_error(self, msg):
+        self.__logger.error(self._format_log_msg(msg))
+
     def _log_debug(self, msg):
         self.__logger.debug(self._format_log_msg(msg))
 
@@ -294,14 +297,20 @@ def transfer_btrfs_snapshot(self,
             # Wait for commands to complete
             send_returncode = send_process.wait()
             receive_returncode = receive_process.wait()
-            if send_returncode:
-                raise subprocess.CalledProcessError(send_process.returncode,
-                                                    send_process.args,
-                                                    send_process.stderr.read())
+
+            def log_process_error(proc_returncode, proc_args, proc_out):
+                proc_out_fmt = proc_out.read().decode().strip()
+                self._log_error('Command %s failed with error code %d (%s)'
+                                % (proc_args, proc_returncode, proc_out_fmt))
+
             if receive_returncode:
-                raise subprocess.CalledProcessError(receive_process.returncode,
-                                                    receive_process.args,
-                                                    receive_process.stdout.read())
+                log_process_error(receive_process.returncode, receive_process.args, receive_process.stdout)
+
+            if send_returncode:
+                log_process_error(send_process.returncode, send_process.args, send_process.stderr)
+
+            if receive_returncode or send_returncode:
+                raise Error("Transferring snapshot failed")
 
         except BaseException as e:
             try: