"alembic current" wont show a head if it's a dependency in another branch

[sqlalchemy-bot]

Migrated issue, originally created by Michael Bayer (@zzzeek)

Create a1->a2->a3, and b1->b2, where b2 is dependent on a2:

#!

[classic@photon2 tmp]$ python -m alembic.config init bug
  Creating directory /home/classic/dev/alembic/tmp/bug ... done
  Creating directory /home/classic/dev/alembic/tmp/bug/versions ... done
  Generating /home/classic/dev/alembic/tmp/bug/README ... done
  Generating /home/classic/dev/alembic/tmp/bug/script.py.mako ... done
  Generating /home/classic/dev/alembic/tmp/alembic.ini ... done
  Generating /home/classic/dev/alembic/tmp/bug/env.py ... done
  Please edit configuration/connection/logging settings in '/home/classic/dev/alembic/tmp/alembic.ini' before proceeding.
[classic@photon2 tmp]$ python -m alembic.config revision -m "a1"
  Generating /home/classic/dev/alembic/tmp/bug/versions/4117fef4729e_a1.py ... done
[classic@photon2 tmp]$ python -m alembic.config revision -m "a2"
  Generating /home/classic/dev/alembic/tmp/bug/versions/4056b039cc5e_a2.py ... done
[classic@photon2 tmp]$ python -m alembic.config revision -m "a3"
  Generating /home/classic/dev/alembic/tmp/bug/versions/5bcdf4f57c00_a3.py ... done
[classic@photon2 tmp]$ python -m alembic.config revision -m "b1" --head=base
  Generating /home/classic/dev/alembic/tmp/bug/versions/a87109c86005_b1.py ... done
[classic@photon2 tmp]$ python -m alembic.config revision -m "b2" --head=a87109c86005 --depends-on=4056b039cc5e
  Generating /home/classic/dev/alembic/tmp/bug/versions/e770df700933_b2.py ... done

upgrade to b2. We see that to satisfy b2, we also need a1 and a2, as well as b1 and b2:

#!

[classic@photon2 tmp]$ python -m alembic.config upgrade e770df700933
INFO  [alembic.runtime.migration] Context impl SQLiteImpl.
INFO  [alembic.runtime.migration] Will assume non-transactional DDL.
INFO  [alembic.runtime.migration] Running upgrade  -> 4117fef4729e, a1
INFO  [alembic.runtime.migration] Running upgrade 4117fef4729e -> 4056b039cc5e, a2
INFO  [alembic.runtime.migration] Running upgrade  -> a87109c86005, b1
INFO  [alembic.runtime.migration] Running upgrade a87109c86005 -> e770df700933, b2

"Current" should show us on a2 and b2, but because a2 is an ancestor of b2 via dependency, we don't see it:

#!

[classic@photon2 tmp]$ python -m alembic.config current
INFO  [alembic.runtime.migration] Context impl SQLiteImpl.
INFO  [alembic.runtime.migration] Will assume non-transactional DDL.
e770df700933 (head)

upgrading from a2 to a3, now we see the two branches again:

#!

[classic@photon2 tmp]$ python -m alembic.config upgrade 5bcdf4f57c00
INFO  [alembic.runtime.migration] Context impl SQLiteImpl.
INFO  [alembic.runtime.migration] Will assume non-transactional DDL.
INFO  [alembic.runtime.migration] Running upgrade 4056b039cc5e -> 5bcdf4f57c00, a3


[classic@photon2 tmp]$ python -m alembic.config current
INFO  [alembic.runtime.migration] Context impl SQLiteImpl.
INFO  [alembic.runtime.migration] Will assume non-transactional DDL.
e770df700933 (head)
5bcdf4f57c00 (head)

[sqlalchemy-bot]

Michael Bayer (@zzzeek) wrote:

Report on other branch dependencies in "current"

Fixed bug where the "alembic current" command wouldn't show a revision
as a current head if it were also a dependency of a version in a
different branch that's also applied. Extra logic is added to
extract "implied" versions on different branches from the top-level
versions listed in the alembic_version table.

Change-Id: I9f485fbc67555d13f737ecffdd25e4c0d8e33f1c
Fixes: #378

→ 6d69285

[sqlalchemy-bot]

Changes by Michael Bayer (@zzzeek):

• changed status to closed