[fix] Catch IOError on tar creation (backup).

locales/en.json

@@ -185,6 +185,7 @@
     "backup_nothings_done" : "There is nothing to save",
     "backup_cleaning_failed" : "Unable to clean backup temporary directory",
     "backup_complete" : "Backup complete",
+    "backup_failed" : "Backup failed",
     "backup_invalid_archive" : "Invalid backup archive",
     "restore_action_required" : "You must specify something to restore",
     "restore_confirm_yunohost_installed" : "Do you really want to restore an already installed system? [{answers:s}]",

src/yunohost/backup.py

@@ -265,29 +265,29 @@ def backup_create(name=None, description=None, output_directory=None,
     if not no_compress:
         logger.info(m18n.n('backup_creating_archive'))
         archive_file = "%s/%s.tar.gz" % (output_directory, name)
-        try:
+        # Create the archives directory
-            tar = tarfile.open(archive_file, "w:gz")
-        except:
-            tar = None
-
-            # Create the archives directory and retry
         if not os.path.isdir(archives_path):
             os.mkdir(archives_path, 0750)
+
+        # Open archive file for writing
         try:
             tar = tarfile.open(archive_file, "w:gz")
         except:
             logger.debug("unable to open '%s' for writing",
                 archive_file, exc_info=1)
-                    tar = None
+
-            else:
-                logger.debug("unable to open '%s' for writing",
-                    archive_file, exc_info=1)
-            if tar is None:
             _clean_tmp_dir(2)
             raise MoulinetteError(errno.EIO,
                 m18n.n('backup_archive_open_failed'))
+
+        # Write into archive
+        try:
             tar.add(tmp_dir, arcname='')
             tar.close()
+        except IOError as e:
+            logger.error(m18n.n('backup_archive_writing_error'), exc_info=1)
+            _clean_tmp_dir(3)
+            raise MoulinetteError(errno.EIO, m18n.n('backup_failed'))
 
         # Move info file
         os.rename(tmp_dir + '/info.json',