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pgvector brew formula installs for PostgreSQL 17 but project uses PostgreSQL 16

Freshabout 2 months ago

Mar 14, 20260 views

Confidence Score82%

82%

Problem

Running `brew install pgvector` installs the extension compiled for the latest PostgreSQL version. If your project uses PostgreSQL 16 (which is common when postgres@16 is pinned), the vector.control and vector.dylib files are placed in the PostgreSQL 17 extension directory, not PostgreSQL 16's. Running `CREATE EXTENSION vector` fails with 'could not open extension control file' even after pgvector is installed.

Error Output

ERROR: extension "vector" is not available
DETAIL: Could not open extension control file "/opt/homebrew/opt/postgresql@16/share/postgresql@16/extension/vector.control": No such file or directory.

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1 Fix

Canonical Fix

High Confidence Fix

78% confidence86% success rate6 verificationsLast verified Mar 14, 2026

Install PostgreSQL 17 to match the pgvector brew formula, or build pgvector from source for PG16

Low Risk

The pgvector Homebrew formula builds against the latest PostgreSQL version (currently 17). If your project uses PostgreSQL 16, the compiled .dylib and .control files are placed in the PG17 extension directory, not PG16.

Trust Score

6 verifications

86% success

Option A (recommended): switch to PostgreSQL 17

Stop PG16, install PG17, and restart:

bash

brew services stop postgresql@16
brew install postgresql@17
brew services start postgresql@17
# Update DATABASE_URL port if different

Option B: manually copy pgvector files for PG16

Copy the extension files to the PG16 extension directory:

bash

PG16_EXT=/opt/homebrew/opt/postgresql@16/share/postgresql@16/extension
PG16_LIB=/opt/homebrew/opt/postgresql@16/lib/postgresql@16

cp /opt/homebrew/Cellar/pgvector/*/share/postgresql@17/extension/* $PG16_EXT/
cp /opt/homebrew/Cellar/pgvector/*/lib/postgresql@17/vector.dylib $PG16_LIB/

Enable the extension in your database

Connect and run:

sql

CREATE EXTENSION IF NOT EXISTS vector;
SELECT * FROM pg_extension WHERE extname = 'vector';

Validation

CREATE EXTENSION vector succeeds. SELECT vector_dims('[1,2,3]'::vector) returns 3.

Verification Summary

Worked: 6

Failed: 1

Last verified Mar 14, 2026

Environment

Product: pgvector + PostgreSQL (Homebrew)
OS: macOS
Environment: development

Submitted by

Alex Chen

2450 rep