Environment Variables

Configure zerobrew behavior using environment variables

Zerobrew can be configured using environment variables to customize installation paths and behavior. These variables can be set in your shell configuration or passed directly when running commands.

Core Variables

ZEROBREW_ROOT · string

The root directory where zerobrew stores all its data, including the package store, cellar, cache, database, and locks.

This directory contains:

• store/ - Content-addressed package storage
• cellar/ - Installed package metadata
• cache/ - Downloaded package archives
• db/ - SQLite database (zb.sqlite3)
• locks/ - File locks for concurrent operations

Platform defaults:

• macOS: /opt/zerobrew
• Linux: $XDG_DATA_HOME/zerobrew (typically ~/.local/share/zerobrew)

Example:

export ZEROBREW_ROOT="$HOME/zerobrew"

ZEROBREW_PREFIX · string

The prefix directory where package binaries and libraries are symlinked. This is the directory you should add to your PATH.

Platform-specific behavior:

• macOS: Defaults to ZEROBREW_ROOT directly (e.g., /opt/zerobrew) to maintain compatibility with Mach-O binary path length constraints (13 characters, same as Homebrew’s /opt/homebrew)
• Linux: Defaults to $ZEROBREW_ROOT/prefix to separate data from the installation prefix

This directory typically contains:

• bin/ - Executable binaries
• lib/ - Shared libraries
• include/ - Header files
• share/ - Shared data files
• etc/ - Configuration files
• opt/ - Individual package directories

Example:

export ZEROBREW_PREFIX="/usr/local"
export PATH="$ZEROBREW_PREFIX/bin:$PATH"

ZEROBREW_AUTO_INIT · boolean · default: "false"

Automatically initialize zerobrew without prompting when running commands for the first time.

When set to true, zerobrew will automatically:

• Create the root and prefix directories
• Set up the internal directory structure
• Initialize the package database

This is useful for:

• CI/CD environments where interactive prompts are not possible
• Automated scripts and provisioning tools
• Docker containers and other non-interactive environments

Example:

export ZEROBREW_AUTO_INIT=true
zb install wget  # Will auto-initialize if needed

Additional Environment Variables

Zerobrew also respects and sets several other environment variables for compatibility and functionality:

Package Config

PKG_CONFIG_PATH · string

Automatically set by zerobrew’s shell initialization to include $ZEROBREW_PREFIX/lib/pkgconfig for pkg-config to find installed libraries.

Example:

export PKG_CONFIG_PATH="$ZEROBREW_PREFIX/lib/pkgconfig:$PKG_CONFIG_PATH"

SSL Certificates

Zerobrew automatically configures SSL certificate paths when available:

CURL_CA_BUNDLE · string

Path to the CA certificate bundle for curl and other tools. Automatically set to one of:

• $ZEROBREW_PREFIX/opt/ca-certificates/share/ca-certificates/cacert.pem
• $ZEROBREW_PREFIX/etc/ca-certificates/cacert.pem
• $ZEROBREW_PREFIX/etc/openssl/cert.pem
• $ZEROBREW_PREFIX/share/ca-certificates/cacert.pem

SSL_CERT_FILE · string

Path to the SSL certificate file. Uses the same priority order as CURL_CA_BUNDLE.

SSL_CERT_DIR · string

Directory containing SSL certificates. Automatically set to one of:

• $ZEROBREW_PREFIX/etc/ca-certificates
• $ZEROBREW_PREFIX/etc/openssl/certs
• $ZEROBREW_PREFIX/share/ca-certificates

Usage Examples

Custom Installation Location

export ZEROBREW_ROOT="$HOME/.zerobrew"
export ZEROBREW_PREFIX="$HOME/.local"
zb install wget

CI/CD Environment

export ZEROBREW_ROOT="/opt/zerobrew"
export ZEROBREW_PREFIX="/opt/zerobrew"
export ZEROBREW_AUTO_INIT=true
zb install jq curl wget

Docker Container

ENV ZEROBREW_ROOT=/opt/zerobrew
ENV ZEROBREW_PREFIX=/opt/zerobrew
ENV ZEROBREW_AUTO_INIT=true
ENV PATH="/opt/zerobrew/bin:$PATH"
RUN zb install git make cmake

Development Setup

# .envrc (for use with direnv)
export ZEROBREW_ROOT="$PWD/.zerobrew"
export ZEROBREW_PREFIX="$PWD/.zerobrew/prefix"
export PATH="$ZEROBREW_PREFIX/bin:$PATH"

CLI Flag Override

Environment variables can be overridden using CLI flags:

# Override ZEROBREW_ROOT
zb --root /custom/path install wget

# Override ZEROBREW_PREFIX
zb --prefix /usr/local install wget

# Override ZEROBREW_AUTO_INIT
zb --auto-init install wget

Priority Order

Zerobrew determines configuration values in the following priority order (highest to lowest):

1. CLI flags - --root, --prefix, --auto-init
2. Environment variables - ZEROBREW_ROOT, ZEROBREW_PREFIX, ZEROBREW_AUTO_INIT
3. Existing installation - If /opt/zerobrew exists, it will be used
4. Platform defaults - macOS uses /opt/zerobrew, Linux uses $XDG_DATA_HOME/zerobrew

On macOS, the prefix must not exceed 13 characters due to Mach-O binary limitations. Zerobrew defaults to using the root directory as the prefix (/opt/zerobrew) to maintain compatibility with Homebrew’s path length.