output error when DROP COLUMN fails

In case it might be caused by something else than SQLite's inability to
delete a column, it's good to have the actual error written out
somewhere.

1 files changed, 8 insertions, 4 deletions

diff --git a/fietsboek/alembic/versions/20221214_c939800af428.py b/fietsboek/alembic/versions/20221214_c939800af428.py
index 79ec899..4b07983 100644
--- a/fietsboek/alembic/versions/20221214_c939800af428.py
+++ b/fietsboek/alembic/versions/20221214_c939800af428.py
@@ -20,14 +20,15 @@ def upgrade():
     # ### commands auto generated by Alembic - please adjust! ###
     try:
         op.drop_column('tracks', 'gpx')
-    except sa.exc.OperationalError:
+    except sa.exc.OperationalError as exc:
         # sqlite < 3.35.0 does not know "ALTER TABLE DROP COLUMN", in which
         # case we probably don't want to break the DB. Instead, we simply
         # "drop" the column by setting it empty, which should still help in
         # saving some space.
         logging.getLogger(__name__).warning(
             "Your database does not support dropping a column. "
-            "We're setting the content to zero instead."
+            "We're setting the content to zero instead (%s).",
+            exc,
         )
         op.execute("UPDATE tracks SET gpx = '';")
     # ### end Alembic commands ###
@@ -36,6 +37,9 @@ def downgrade():
     # ### commands auto generated by Alembic - please adjust! ###
     try:
         op.add_column('tracks', sa.Column('gpx', sa.BLOB(), nullable=True))
-    except sa.exc.OperationalError:
-        logging.getLogger(__name__).warning("The column already exists.")
+    except sa.exc.OperationalError as exc:
+        logging.getLogger(__name__).warning(
+            "The column already exists - doing nothing (%s).",
+            exc,
+        )
     # ### end Alembic commands ###