psycopg register_shapely ignores SRID causing SRID

The Fix

Adds SRID support to shapely dumpers/loaders, resolving issues with SRID mismatches when dumping geometries.

Based on closed psycopg/psycopg issue #1028 · PR/commit linked

Production note: Most teams hit this during upgrades or environment changes. Roll out with a canary and smoke critical endpoints (health, OpenAPI/docs) before 100%.

Jump to Verify Open PR/Commit

@@ -40,7 +40,7 @@ jobs:
           - {impl: python, python: "3.9", ext: gevent, postgres: "postgres:17"}
           - {impl: python, python: "3.9", ext: dns, postgres: "postgres:14"}
-          - {impl: python, python: "3.9", ext: postgis, postgres: "postgis/postgis"}
+          - {impl: python, python: "3.12", ext: postgis, postgres: "postgis/postgis"}
           - {impl: python, python: "3.10", ext: numpy, postgres: "postgres:14"}

repro.py

class BaseGeometryBinaryDumper(Dumper):
    format = Format.BINARY

    def dump(self, obj: BaseGeometry) -> Buffer:
        return to_wkb(obj, include_srid=True)


class BaseGeometryDumper(Dumper):
    def dump(self, obj: BaseGeometry) -> Buffer:
        return to_wkb(obj, True, include_srid=True).encode()

verify

Re-run the minimal reproduction on your broken version, then apply the fix and re-run.

fix.md

Option A — Apply the official fix\nAdds SRID support to shapely dumpers/loaders, resolving issues with SRID mismatches when dumping geometries.\nWhen NOT to use: Do not use this fix if SRID handling is not required in your application.\n\n

Why This Fix Works in Production

Trigger: register_shapely ignores SRID causing SRID missmatch errors
Mechanism: The dumper logic ignored SRID when dumping geometries, causing mismatches

Production impact:

If left unfixed, the same config can fail only in production (env differences), causing startup failures or partial feature outages.

Why This Breaks in Prod

The dumper logic ignored SRID when dumping geometries, causing mismatches
Production symptom (often without a traceback): register_shapely ignores SRID causing SRID missmatch errors

Proof / Evidence

GitHub issue: #1028
Fix PR: https://github.com/psycopg/psycopg/pull/1033
Reproduced locally: No (not executed)
Last verified: 2026-02-09
Confidence: 0.70
Did this fix it?: Yes (upstream fix exists)
Own content ratio: 0.57

Discussion

High-signal excerpts from the issue thread (symptoms, repros, edge-cases).

Jump to Sources Open on GitHub

“Hello, thank you for your input”

@dvarrazzo · 2025-03-19 · source

Failure Signature (Search String)

register_shapely ignores SRID causing SRID missmatch errors

Copy-friendly signature

signature.txt

Failure Signature
-----------------
register_shapely ignores SRID causing SRID missmatch errors

Error Message

Signature-only (no traceback captured)

error.txt

Error Message
-------------
register_shapely ignores SRID causing SRID missmatch errors

Minimal Reproduction

repro.py

class BaseGeometryBinaryDumper(Dumper):
    format = Format.BINARY

    def dump(self, obj: BaseGeometry) -> Buffer:
        return to_wkb(obj, include_srid=True)


class BaseGeometryDumper(Dumper):
    def dump(self, obj: BaseGeometry) -> Buffer:
        return to_wkb(obj, True, include_srid=True).encode()

What Broke

SRID mismatches led to incorrect geometry representations in production.

Why It Broke

The dumper logic ignored SRID when dumping geometries, causing mismatches

Fix Options (Details)

Option A — Apply the official fix

Adds SRID support to shapely dumpers/loaders, resolving issues with SRID mismatches when dumping geometries.

When NOT to use: Do not use this fix if SRID handling is not required in your application.

Fix reference: https://github.com/psycopg/psycopg/pull/1033

Last verified: 2026-02-09. Validate in your environment.

When NOT to Use This Fix

Do not use this fix if SRID handling is not required in your application.

Verify Fix

verify

Re-run the minimal reproduction on your broken version, then apply the fix and re-run.

Did This Fix Work in Your Case?

Quick signal helps us prioritize which fixes to verify and improve.

Prevention

Capture the exact failing error string in logs and tests so you can reproduce via a minimal script.
Pin production dependencies and upgrade only with a reproducible test that hits the failing path.

Related Issues

No related fixes found.

Cluster: psycopg:configuration-error All hubs All clusters

Related clusters: Data consistency Timeout Race condition

Sources

We don’t republish the full GitHub discussion text. Use the links above for context.

psycopg register_shapely ignores SRID causing SRID missmatch errors (Fix)