Setting Up pg_gembed on Windows with MSYS2 & MinGW

This guide walks you through setting up the pg_gembed PostgreSQL extension on Windows using MSYS2 and the MinGW-w64 (UCRT64) toolchain.

Prerequisites

Download and install MSYS2 from the official website:

👉 https://www.msys2.org/

After installation, open the UCRT64 terminal (recommended) from the MSYS2 start menu entries.

1. Install Required Dependencies

Run the following commands inside the MSYS2 terminal to install all required packages:

# Git
pacman -S git

# PostgreSQL (UCRT64 build)
pacman -S mingw-w64-ucrt-x86_64-postgresql

# Make and pkg-config
pacman -S make mingw-w64-ucrt-x86_64-pkgconf

# Rust toolchain
pacman -S mingw-w64-ucrt-x86_64-rust

# CA certificates (needed for secure connections)
pacman -S ca-certificates
update-ca-trust

2. Update the PATH

Add the UCRT64 binaries to your PATH so tools like pg_config, psql, etc. are available:

export PATH=$PATH:/c/msys64/ucrt64/bin

Tip: Add this line to your ~/.bashrc or ~/.bash_profile to make it permanent across sessions.

3. Initialize and Start PostgreSQL

# Initialize the database cluster
initdb -D /usr/local/var/postgres

# Start the PostgreSQL server (logs to "logfile")
pg_ctl -D /usr/local/var/postgres -l logfile start

# Create a database for your user (replace <username> with your username)
createdb <username>

4. Install the pgvector Extension

pg_gembed depends on pgvector for vector storage support.

git clone --branch v0.8.2 https://github.com/pgvector/pgvector.git
cd pgvector
make install
cd ..

5. Build and Install pg_gembed

# Clone the main extension repository
git clone https://github.com/JoelDiaz222/pg_gembed
cd pg_gembed

# Clone the Rust embedding library (gembed)
git clone https://github.com/JoelDiaz222/gembed
cd gembed

# Build the Rust library in release mode
# (SSL verification is disabled for corporate/self-signed certificate environments)
GIT_SSL_NO_VERIFY=true CARGO_NET_GIT_FETCH_WITH_CLI=true cargo build --release

cd ..

# Install the PostgreSQL extension
make install

6. Enable the Extensions in PostgreSQL

Connect to PostgreSQL and activate both extensions:

psql

Inside the psql prompt:

CREATE EXTENSION vector;
CREATE EXTENSION pg_gembed;

Troubleshooting

Issue Solution
pg_config not found Make sure /c/msys64/ucrt64/bin is in your PATH
SSL errors during cargo build Use GIT_SSL_NO_VERIFY=true as shown in step 5
initdb fails Ensure no existing PostgreSQL data directory exists at the target path
pacman package not found Run pacman -Syu first to update the package database