Perl Environment Setup

Guide for setting up Perl development environments using perlbrew for version management.

perlbrew Overview

perlbrew manages multiple Perl installations in user space without root access.

Benefits

• Install any Perl version without root
• Switch between versions instantly
• Isolated module installations per version
• Test against multiple Perl versions

Installation

Quick Install

# Download and run installer
curl -L https://install.perlbrew.pl | bash

# Initialize perlbrew
perlbrew init

# Add to shell profile (~/.bashrc or ~/.zshrc)
source ~/perl5/perlbrew/etc/bashrc

Verify Installation

perlbrew version
perlbrew list
which perl

Installing Perl Versions

List Available Versions

# Show all available versions
perlbrew available

# Show only stable releases
perlbrew available | grep -E '^\s*perl-5\.\d+\.\d+$'

Install a Version

# Install latest stable
perlbrew install perl-5.38.2

# Install with threading
perlbrew install perl-5.38.2 -Dusethreads

# Install with optimizations
perlbrew install perl-5.38.2 -Doptimize=-O2

# Quick install (skip tests)
perlbrew install perl-5.38.2 --notest

# Install with custom name
perlbrew install perl-5.38.2 --as perl-5.38-dev

Common Build Options

Option	Purpose
-Dusethreads	Enable thread support
-Duseithreads	Enable interpreter threads
--notest	Skip test suite (faster)
-j N	Parallel build with N jobs
--as NAME	Custom installation name

Switching Versions

# Switch for current shell
perlbrew use perl-5.38.2

# Set permanent default
perlbrew switch perl-5.38.2

# Temporary switch with command
perlbrew exec --with perl-5.38.2 perl -v

# Return to system Perl
perlbrew switch-off
perlbrew off  # Shortcut

Managing Installations

# List installed versions
perlbrew list

# Show current version
perlbrew info

# Remove a version
perlbrew uninstall perl-5.36.0

# Upgrade perlbrew itself
perlbrew self-upgrade

Library Management

perlbrew lib creates isolated module environments per Perl version.

Create Libraries

# Create a library for a project
perlbrew lib create perl-5.38.2@myproject

# List libraries
perlbrew lib list

# Switch to library
perlbrew use perl-5.38.2@myproject

# Delete library
perlbrew lib delete perl-5.38.2@myproject

Per-Project Libraries

# Create project-specific environment
perlbrew lib create perl-5.38.2@webapp

# Install modules to this library
perlbrew use perl-5.38.2@webapp
cpanm Mojolicious DBIx::Class

# Switch between project environments
perlbrew use perl-5.38.2@webapp
perlbrew use perl-5.38.2@cli-tools

cpanm Integration

# Install cpanm for current Perl
perlbrew install-cpanm

# Now cpanm is available
cpanm Module::Name

Testing Across Versions

# Run command with all installed Perls
perlbrew exec perl -v

# Run tests with all versions
perlbrew exec prove -l t/

# Run with specific versions
perlbrew exec --with perl-5.36.0,perl-5.38.2 prove t/

Shell Integration

Bash/Zsh

Add to ~/.bashrc or ~/.zshrc:

source ~/perl5/perlbrew/etc/bashrc

Fish

Add to ~/.config/fish/config.fish:

source ~/perl5/perlbrew/etc/perlbrew.fish

Project Configuration

.perl-version File

Create a .perl-version file in project root (for tools that support it):

5.38.2

Project Setup Script

#!/bin/bash
# setup-perl-env.sh

PERL_VERSION="perl-5.38.2"
PROJECT_LIB="myproject"

# Ensure perlbrew is loaded
source ~/perl5/perlbrew/etc/bashrc

# Install Perl if needed
if ! perlbrew list | grep -q "$PERL_VERSION"; then
    perlbrew install "$PERL_VERSION" --notest
fi

# Create project library if needed
if ! perlbrew lib list | grep -q "$PROJECT_LIB"; then
    perlbrew lib create "${PERL_VERSION}@${PROJECT_LIB}"
fi

# Switch to project environment
perlbrew use "${PERL_VERSION}@${PROJECT_LIB}"

# Install cpanm if needed
command -v cpanm >/dev/null || perlbrew install-cpanm

# Install project dependencies
cpanm --installdeps .

echo "Environment ready: $(perl -v | grep version)"

Directory Structure

perlbrew creates this structure:

~/perl5/perlbrew/
├── bin/           # perlbrew executable
├── build/         # Temporary build files
├── dists/         # Downloaded Perl sources
├── etc/           # Shell integration scripts
└── perls/         # Installed Perl versions
    ├── perl-5.36.0/
    └── perl-5.38.2/

Troubleshooting

Build Failures

# Check build log
less ~/perl5/perlbrew/build.perl-5.38.2.log

# Install build dependencies
# Debian/Ubuntu
sudo apt install build-essential

# Install with verbose output
perlbrew --verbose install perl-5.38.2

Path Issues

# Verify perlbrew is loaded
which perl
# Should show ~/perl5/perlbrew/perls/...

# Check current environment
perlbrew info

# Force reload
source ~/perl5/perlbrew/etc/bashrc

Cleanup

# Remove build artifacts
perlbrew clean

# Remove downloaded source archives
rm -rf ~/perl5/perlbrew/dists/*

Recommended Setup

For new development machines:

# 1. Install perlbrew
curl -L https://install.perlbrew.pl | bash
source ~/perl5/perlbrew/etc/bashrc

# 2. Install latest stable Perl
perlbrew install perl-5.38.2 --notest
perlbrew switch perl-5.38.2

# 3. Install cpanm
perlbrew install-cpanm

# 4. Install essential modules
cpanm App::cpanoutdated
cpanm Perl::Critic
cpanm Perl::Tidy

# 5. Add to shell profile
echo 'source ~/perl5/perlbrew/etc/bashrc' >> ~/.bashrc

Alternative: plenv

plenv is an alternative to perlbrew inspired by rbenv:

# Install plenv
git clone https://github.com/tokuhirom/plenv.git ~/.plenv
git clone https://github.com/tokuhirom/Perl-Build.git ~/.plenv/plugins/perl-build/

# Add to PATH
echo 'export PATH="$HOME/.plenv/bin:$PATH"' >> ~/.bashrc
echo 'eval "$(plenv init -)"' >> ~/.bashrc

# Install Perl
plenv install 5.38.2
plenv global 5.38.2
plenv install-cpanm

plenv advantages:

• Simpler architecture (shims-based)
• Faster shell startup
• Per-directory version files (.perl-version)

perlbrew advantages:

• More mature and widely used
• Better library management
• More configuration options

Additional Resources

For CPAN module management, see the perl-cpan-ecosystem skill.