'alembic history' ignores env.py

[sqlalchemy-bot]

Migrated issue, originally created by rkrzr (@rkrzr)

We rely on env.py to set the correct PYTHONPATH, so that we can import our modules in an alembic migration. This works for all commands (e.g. alembic current, alembic upgrade, alembic downgrade), except for alembic history.

For alembic history it fails with: ModuleNotFoundError: No module named 'bla'

It seems that alembic history does not read in env.py.

The workaround for this is to run PYTHONPATH=. alembic history, which works correctly.

[sqlalchemy-bot]

Michael Bayer (@zzzeek) wrote:

make sure you have revision_environment=True in your alembic.ini and let me know if this patch provides everything:

diff --git a/alembic/command.py b/alembic/command.py
index 0280528..503c6a9 100644
--- a/alembic/command.py
+++ b/alembic/command.py
@@ -342,6 +342,10 @@ def history(config, rev_range=None, verbose=False):
     else:
         base = head = None
 
+    environment = util.asbool(
+        config.get_main_option("revision_environment")
+    )
+
     def _display_history(config, script, base, head):
         for sc in script.walk_revisions(
                 base=base or "base",
@@ -370,6 +374,8 @@ def history(config, rev_range=None, verbose=False):
         _display_history_w_current(config, script, head=head)
     elif head == "current":
         _display_history_w_current(config, script, base=base)
+    elif environment:
+        _display_history_w_current(config, script, base, head)
     else:
         _display_history(config, script, base, head)

[sqlalchemy-bot]

Changes by Michael Bayer (@zzzeek):

• removed labels: bug
• added labels: feature

[sqlalchemy-bot]

Changes by Michael Bayer (@zzzeek):

• added labels: command interface

[sqlalchemy-bot]

Changes by Michael Bayer (@zzzeek):

• set milestone to "fasttrack"

[sqlalchemy-bot]

Michael Bayer (@zzzeek) wrote:

bzzt, try again

diff --git a/alembic/command.py b/alembic/command.py
index 0280528..8675005 100644
--- a/alembic/command.py
+++ b/alembic/command.py
@@ -342,6 +342,10 @@ def history(config, rev_range=None, verbose=False):
     else:
         base = head = None
 
+    environment = util.asbool(
+        config.get_main_option("revision_environment")
+    )
+
     def _display_history(config, script, base, head):
         for sc in script.walk_revisions(
                 base=base or "base",
@@ -357,6 +361,8 @@ def history(config, rev_range=None, verbose=False):
                 _display_history(config, script, base, rev)
             elif base is None:
                 _display_history(config, script, rev, head)
+            else:
+                _display_history(config, script, base, head)
             return []
 
         with EnvironmentContext(
@@ -370,6 +376,8 @@ def history(config, rev_range=None, verbose=False):
         _display_history_w_current(config, script, head=head)
     elif head == "current":
         _display_history_w_current(config, script, base=base)
+    elif environment:
+        _display_history_w_current(config, script, base, head)
     else:
         _display_history(config, script, base, head)

[sqlalchemy-bot]

Michael Bayer (@zzzeek) wrote:

https://gerrit.sqlalchemy.org/507

[sqlalchemy-bot]

Michael Bayer (@zzzeek) wrote:

Use env in history when revision_history=true

The alembic history command will now make use of the revision
environment env.py unconditionally if the revision_environment
configuration flag is set to True. Previously, the environment would
only be invoked if the history specification were against a database-stored
revision token.

Change-Id: I2f9dc2554c8a4523f93248859587e8e276fe4d4a
Fixes: #447

→ 4effc81

[sqlalchemy-bot]

Changes by Michael Bayer (@zzzeek):

• changed status to closed

[sqlalchemy-bot]

rkrzr (@rkrzr) wrote:

Thanks for the quick fix! I can confirm that alembic history now works as expected.

[sqlalchemy-bot]

Mischa (@mischas) wrote:

"heads" doesn't seem to be running env.py either, with or without revision_history=true

[sqlalchemy-bot]

Michael Bayer (@zzzeek) wrote:

Probably not open a new issue please

[sqlalchemy-bot]

Michael Bayer (@zzzeek) wrote:

looking at #460 I'm wondering if I just acted too quickly here. Wouldn't it be easier to just have your PYTHONPATH set up in your alembic.ini file if such an option could be added?