[Toaster] Weird migration issue

[Barros Pena, Belen]

I've been coming across a problem with migrations occasionally (and rather
randomly) when I start Toaster. At the beginning it seemed I was the only
one seeing this. But, while at ELC, someone came to me because they were
having the same problem. His trace is below. Restarting the host seems to
solve the problem for me. In his case, he tried a different host and
everything worked. 

It doesn't seem distro-related: his was CentOS, mine Ubuntu. That's all I
know. Michael Wood looked at this briefly, so he might have something to
add. It was not a problem when it was just me, but if other people are
seeing this, then I am bit more worried.

Any ideas on what could be causing it?

Cheers

Belén

File 
"/state/partition1/scratch/tartler/yocto-master/poky/bitbake/bin/../lib/toa
ster/manage.py", line 10, in <module>
    execute_from_command_line(sys.argv)
  File 
"/state/partition1/scratch/tartler/yocto-master/poky/build/venv/lib/python2
.7/site-packages/django/core/management/__init__.py", line 354, in
execute_from_command_line
    utility.execute()
  File 
"/state/partition1/scratch/tartler/yocto-master/poky/build/venv/lib/python2
.7/site-packages/django/core/management/__init__.py", line 346, in execute
    self.fetch_command(subcommand).run_from_argv(self.argv)
  File 
"/state/partition1/scratch/tartler/yocto-master/poky/build/venv/lib/python2
.7/site-packages/django/core/management/base.py", line 394, in
run_from_argv
    self.execute(*args, **cmd_options)
  File 
"/state/partition1/scratch/tartler/yocto-master/poky/build/venv/lib/python2
.7/site-packages/django/core/management/base.py", line 445, in execute
    output = self.handle(*args, **options)
  File 
"/state/partition1/scratch/tartler/yocto-master/poky/build/venv/lib/python2
.7/site-packages/django/core/management/commands/migrate.py", line 222, in
handle
    executor.migrate(targets, plan, fake=fake, fake_initial=fake_initial)
  File 
"/state/partition1/scratch/tartler/yocto-master/poky/build/venv/lib/python2
.7/site-packages/django/db/migrations/executor.py", line 110, in migrate
    self.apply_migration(states[migration], migration, fake=fake,
fake_initial=fake_initial)
  File 
"/state/partition1/scratch/tartler/yocto-master/poky/build/venv/lib/python2
.7/site-packages/django/db/migrations/executor.py", line 148, in
apply_migration
    state = migration.apply(state, schema_editor)
  File 
"/state/partition1/scratch/tartler/yocto-master/poky/build/venv/lib/python2
.7/site-packages/django/db/backends/base/schema.py", line 93, in __exit__
    self.atomic.__exit__(exc_type, exc_value, traceback)
  File 
"/state/partition1/scratch/tartler/yocto-master/poky/build/venv/lib/python2
.7/site-packages/django/db/transaction.py", line 228, in __exit__
    connection.rollback()
  File 
"/state/partition1/scratch/tartler/yocto-master/poky/build/venv/lib/python2
.7/site-packages/django/db/backends/base/base.py", line 183, in rollback
    self._rollback()
  File 
"/state/partition1/scratch/tartler/yocto-master/poky/build/venv/lib/python2
.7/site-packages/django/db/backends/base/base.py", line 147, in _rollback
    return self.connection.rollback()
  File 
"/state/partition1/scratch/tartler/yocto-master/poky/build/venv/lib/python2
.7/site-packages/django/db/utils.py", line 98, in __exit__
    six.reraise(dj_exc_type, dj_exc_value, traceback)
  File 
"/state/partition1/scratch/tartler/yocto-master/poky/build/venv/lib/python2
.7/site-packages/django/db/backends/base/base.py", line 147, in _rollback
    return self.connection.rollback()
django.db.utils.OperationalError: cannot rollback - no transaction is
active
Failed migrations, aborting system start
Failed start.