IndexError: string index out of range in trac-admin upgrade

[benjamin@…]

When I try to upgrade from 0.11.7 to 0.12 I get the following output. I really have no clue at all where I should start looking.

Trac was installed using Gentoo's emerge trac, python version is 2.6.5-r3, sqlite 3.6.23.1 and pysqlite 2.6.0

trac-admin .
Willkommen bei trac-admin 0.12
Interaktive Administrations-Konsole von Trac
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Geben Sie '?' oder 'help' für Hilfe zu den Kommandos ein.
        
Trac [trac]> upgrade
IndexError: string index out of range

[Remy Blank]

That's not a useful error message, granted. But you should have a full traceback in the log. Could you please post it here?

[anonymous]

Sorry I didn't have a look in the log/trac.log since I exspected the trace to show up in the console. But here it is

2010-08-07 19:32:06,531 Trac[console] ERROR: Exception in trac-admin command: 
Traceback (most recent call last):
  File "/usr/lib64/python2.6/site-packages/trac/admin/console.py", line 107, in onecmd
    rv = cmd.Cmd.onecmd(self, line) or 0
  File "/usr/lib64/python2.6/cmd.py", line 218, in onecmd
    return self.default(line)
  File "/usr/lib64/python2.6/site-packages/trac/admin/console.py", line 257, in default
    return cmd_mgr.execute_command(*args)
  File "/usr/lib64/python2.6/site-packages/trac/admin/api.py", line 123, in execute_command
    return f(*fargs)
  File "/usr/lib64/python2.6/site-packages/trac/env.py", line 790, in _do_upgrade
    self.env.upgrade(backup=no_backup is None)
  File "/usr/lib64/python2.6/site-packages/trac/env.py", line 528, in upgrade
    self.backup(backup_dest)
  File "/usr/lib64/python2.6/site-packages/trac/env.py", line 500, in backup
    return DatabaseManager(self).backup(dest)
  File "/usr/lib64/python2.6/site-packages/trac/db/api.py", line 169, in backup
    if backup_dir[0] != "/":
IndexError: string index out of range

[Remy Blank]

It seems that Trac is choking on your [trac] backup_dir option being empty. Could you please try the following patch:

trac/db/api.py

@@ -166 +166 @@
         connector, args = self.get_connector()
         if not dest:
             backup_dir = self.backup_dir
-            if backup_dir[0] != "/":
+            if not os.path.isabs(backup_dir):
                 backup_dir = os.path.join(self.env.path, backup_dir)
             db_str = self.config.get('trac', 'database')
             db_name, db_path = db_str.split(":", 1)

Note that an empty value for the option above means that database backups will be stored in the root of your Trac environment. That's not necessarily a good idea.

[Remy Blank]

Patch confirmed on IRC, and applied in [9989].