django - remove a migration from south migration history -

i have app named 'robots' , used 0.9 version of it

i later find out 0.9 has feature don't want , downgraded 0.8

after sometime, try south migrate on project , meet error south.exceptions.nomigrations: application '<module 'robots' '/home/ubuntu/virtualenvs/codingqna/local/lib/python2.7/site-packages/robots/__init__.pyc'>' has no migrations.

i guess 0.9 had migrations file 0.8 doesn't, , south complaining it.

how remove south's history never existed? (like used 0.8 beginning without migrations files)

or other way can use here?

delete south_migrationhistory app_name='robots'; 

south_migrationhistory table keeps track of migrations have been applied , yet applied. since 0.8 of robots doesn't have migration files entries table south_migrationhistory can removed , won't affect else.