CLI error when log file can't be opened (#326)

beets/ui/commands.py

@@ -580,7 +580,11 @@ def import_files(lib, paths, copy, write, autot, logpath, art, threaded,
     # Open the log.
     if logpath:
         logpath = normpath(logpath)
-        logfile = open(syspath(logpath), 'a')
+        try:
+            logfile = open(syspath(logpath), 'a')
+        except IOError:
+            raise ui.UserError(u"could not open log file for writing: %s" %
+                               displayable_path(logpath))
         print >>logfile, 'import started', time.asctime()
     else:
         logfile = None

docs/changelog.rst

@@ -17,6 +17,8 @@ Changelog
   to "Various Artists".
 * The ``inline`` plugin now prints a more comprehensible error when exceptions
   occur in Python snippets.
+* A reasonable error message is now shown when the import log file cannot be
+  opened.
 * Fix a bug in the ``rewrite`` plugin that broke the use of multiple rules for
   a single field.
 * Fix a crash with non-ASCII characters in bytestring metadata fields (e.g.,
@@ -26,7 +28,6 @@ Changelog
 * Fix a crash in the ``chroma`` plugin when the Acoustid database had no
   recording associated with a fingerprint.
 
-
 1.0b12 (January 16, 2012)
 -------------------------