#5307 renamed 161_attachment_task_id -> 164 (and 162_..._index -> 165) to
resolve a prefix collision. schema_migrations keys on the full stem, so any DB
that applied the migration under its old 161 number does not have "164" in the
ledger and the runner re-applies the renamed file. The bare `ADD COLUMN task_id`
then aborts with 42701 ("column already exists"), blocking every later
migration — this is exactly what crashed the dev deploy of main (bf288349f) at
container startup, before it ever reached 166_project_dates.
Add `IF NOT EXISTS` so the re-run is a harmless no-op on already-migrated DBs
(dev/staging/prod) with no manual schema_migrations surgery, while staying
identical on a fresh DB. Sibling 165 already uses CREATE INDEX ... IF NOT EXISTS
for the same reason; this brings 164 in line. The down file already uses
DROP COLUMN IF EXISTS.
Verified on a throwaway DB reproducing the dev drift (forget 164/165 in the
ledger, keep the column+index): old file reproduces the 42701 crash, the fixed
file self-heals and completes. Migration lint + concurrent migrate tests pass.
Refs #5307
Co-authored-by: J <j@multica.ai>
Co-authored-by: multica-agent <github@multica.ai>
`161_attachment_task_id` and `162_attachment_task_id_index` (from #5164)
merged after prefixes 161/162/163 were already taken on main by #5277,
#5279, and #5296, leaving two migrations on each of 161 and 162. That trips
TestMigrationNumericPrefixesStayUniqueAfterLegacySet, so the backend job now
fails on every open PR. Renumber to the next free prefixes (164/165); the
file contents are unchanged.
Note for already-migrated databases: any DB that applied 161/162 has those
versions recorded in schema_migrations. After this rename, reconcile the
ledger (rename the recorded versions to 164/165) or reset the dev DB —
otherwise the migrator re-runs the renamed files and the ADD COLUMN fails
because the column already exists.
Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
