🥤 grew

A lean, mean, package-managing machine. In Go.

grew is what happens when you look at your package manager and think: "This could be so much simpler." Deterministic installs. Clean symlinks. A doctor that actually tells you what's wrong. No drama.

💬 A word from the author: I've been a die-hard Homebrew user for longer than I care to admit. brew and I? We go way back. Late nights, broken PATH, the works — and I loved every minute of it. I love brew so much, in fact, that I thought: "What if I just… made it better?" Audacious? Absolutely. Foolish? Possibly. Fun? You bet. grew is my love letter to brew — written in Go, with a cheeky grin.

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✨ What it does

• 📦 Formula + cask installs with SHA256 verification (no funny business)
• 🔒 Sandboxed source builds using macOS Seatbelt or Linux namespaces to keep your system safe
• 🔐 Sandboxed post-install scripts — keg is read-only, network denied, minimal env (Homebrew runs these unsandboxed)
• ✍️ Ed25519 bottle signing — cryptographic signatures on downloads, verified against a local trust store
• 🏷️ Signed tap verification — refuse or warn on unsigned git commits in tap repos (HOMEGREW_TAP_VERIFY)
• 📋 Install snapshots — per-file SHA256 manifests recorded at install time for integrity verification
• 📌 Lockfile — pin exact versions, hashes, and dependency trees for reproducible environments
• 🔗 Deterministic linking with opt symlinks and dry-run support (look before you link)
• 🔄 Keg relocation — rewrites hardcoded library paths in bottles at install time via install_name_tool (macOS) and patchelf (Linux), so binaries just work without DYLD_LIBRARY_PATH hacks
• 🌳 Dependency resolver with an optional tree view (for the visually inclined)
• 🩺 Doctor that checks perms, HTTPS, broken links, snapshot integrity, stale kegs, and cask notarization
• 🛡️ Hardened command execution — -- end-of-options on all external commands, POSIX shell quoting via shellescape, XML-safe plist generation, systemd specifier escaping
• 🧱 Zip Slip protection — archive extraction validates symlink indirection to prevent writes outside the destination
• 🔍 Vulnerability scanning — queries OSV.dev for known CVEs, checks signatures, permissions, and file integrity
• 🪵 Structured logging via log/slog with CLI-friendly output (DEBUG/INFO/WARN/ERROR levels, -v/-d flags)
• 🐚 Alias + shellenv helpers so your workflows stay snappy

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🚀 Getting Started

Get Grew

go install github.com/homegrew/grew/tools/getgrew
getgrew && sudo grew setup

Build from source

Prerequisites: Go 1.26+, git, and a dream.

git clone https://github.com/homegrew/grew.git
cd grew
make build          # or: go generate ./internal/... && go build -o grew

Set up the prefix

grew needs a home — a directory tree for the Cellar, symlinks, taps, and config. The setup command creates it and copies the binary into place:

sudo ./grew setup   # macOS ARM → /opt/homegrew, Intel/Linux → /usr/local/homegrew

The system prefix isolates sandboxed builds from $HOME, preventing them from reaching ~/.ssh, ~/.gnupg, or other sensitive dotfiles. After setup, ownership is transferred to your user — no root needed at runtime.

Wire up your shell

Add this to your shell profile so grew-installed binaries and libraries are available:

# bash (~/.bashrc) or zsh (~/.zshrc)
eval "$(grew shellenv)"

# fish (~/.config/fish/config.fish)
grew shellenv fish | source

Install something

grew install jq
grew install --cask firefox

That's it. No dark rituals. No 47-step setup guide.

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📖 Usage

grew install jq              # the classic
grew install -s ldns         # build from source, like a purist
grew install --cask firefox  # going big
grew link jq                 # stitch it in
grew deps --tree jq          # what hath jq wrought
grew upgrade                 # stay fresh
grew cleanup -n              # peek before you sweep
grew verify jq               # check installed files against manifest
grew vuln-scan               # scan for CVEs and integrity issues
grew lock                    # pin your environment
grew audit --strict          # lint your formulas

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🗺️ Commands

Command	What it does
install	Install a formula or cask (-s to build from source)
uninstall	Send it to the void
list	See what you've collected
info	Stalk a package
search	Find the thing
link	Weave a formula into your PATH
unlink	Cut the thread
update	Refresh tap definitions
upgrade	Get the new hotness
outdated	The hall of shame
reinstall	Uninstall + install from scratch
cleanup	Marie Kondo your Cellar
deps	Dependency spelunking
alias	Name things your way
verify	Check installed packages against their snapshot manifests
audit	Lint formula/cask definitions for quality and security
lock	Generate, check, or show a reproducible lockfile
sign	Sign formula SHA256 hashes with an Ed25519 key
services	Manage background services (start, stop, restart, list)
setup	One-time prefix setup (requires sudo)
doctor	It's not a bug, it's a misconfiguration
vuln-scan	Scan installed packages for security vulnerabilities
config	What grew thinks it knows
shellenv	Wire up your shell
pin / unpin	Freeze a formula to prevent upgrades
completion	Generate shell completion (bash, zsh, fish)
help	You got this

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⚙️ Configuration

grew keeps its stuff tidy under one roof. Tweak it with env vars:

Variable	Default	What it is
HOMEGREW_PREFIX	(inferred from binary location)	Root of the grew tree
HOMEGREW_APPDIR	/Applications	Where casks live
HOMEGREW_TAP_VERIFY	off	Tap commit signature policy (off, warn, strict)
HOMEGREW_ALLOWED_HOSTS	(built-in allowlist)	Additional hosts for SSRF-protected downloads

Everything else flows from the prefix:

/opt/homegrew/              (or /usr/local/homegrew on Intel/Linux)
├── Cellar/        ← installed packages (each keg has a .MANIFEST.json)
├── Taps/          ← formula definitions (git-cloned or API-fetched)
├── bin/           ← symlinked binaries
├── lib/           ← symlinked libraries
├── include/       ← symlinked headers
├── opt/           ← per-formula keg symlinks
├── etc/           ← trusted-keys (Ed25519 public keys, one per line)
├── tmp/           ← ephemeral stuff
├── var/log/       ← audit log
└── grew.lock      ← lockfile (opt-in, created by `grew lock`)

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🛠️ Development

make check         # go test -v -race ./...
make build         # go generate + go build (release — requires root at runtime)
make dev           # go generate + go build -tags devmode (developer build)
make lint          # golangci-lint (if installed)

Developer mode

Release builds require root (sudo grew setup). For local development you can build with the devmode tag and pass --unsafe to setup to install to ~/.homegrew without root:

make dev
./grew setup --unsafe    # installs to ~/.homegrew as your user
./grew install jq        # works without root

Both gates are required — the build tag compiles in the code path, and --unsafe activates it at setup time. Release binaries ignore --unsafe entirely.

Project layout

grew/
├── internal/
│   ├── cmd/          ← CLI commands (the face)
│   ├── cellar/       ← installed package management
│   ├── config/       ← prefix + path resolution
│   ├── depgraph/     ← dependency resolution (Kahn's toposort)
│   ├── downloader/   ← HTTP download + SHA256 + archive extraction (Zip Slip protected)
│   ├── flags/        ← global CLI flags (-v, -d) shared across all subcommands
│   ├── formula/      ← formula parsing and validation
│   ├── cask/         ← cask parsing and Caskroom
│   ├── linker/       ← deterministic symlink management
│   ├── lockfile/     ← reproducible environment pinning
│   ├── logger/       ← CLI-friendly log/slog handler (DEBUG/INFO/WARN/ERROR)
│   ├── relocation/   ← keg relocation (rewrite dylib/ELF paths via install_name_tool/patchelf)
│   ├── runtime/      ← runtime environment (root detection, prefix, devmode gate)
│   ├── sandbox/      ← build + post-install sandboxing (macOS/Linux, shell-safe quoting)
│   ├── service/      ← background service management (launchd/systemd, properly escaped)
│   ├── signing/      ← Ed25519 bottle signing + trust store
│   ├── snapshot/     ← per-file manifest capture + integrity verification
│   ├── tap/          ← tap repo management + commit verification
│   └── version/      ← embedded version from git tags
├── pkg/
│   └── validation/   ← name/version/SHA256/path validation (shared across packages)
└── tools/            ← import scripts (Homebrew formula/cask conversion)

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🔐 Security Model

grew is designed to be more secure than Homebrew out of the box:

Feature	grew	Homebrew
Bottle signing	Ed25519 signatures verified against local trust store	None — relies on HTTPS + SHA256 only
Tap verification	Optional GPG/SSH commit signature enforcement	None
Post-install sandbox	Read-only keg, no network, minimal env	Unsandboxed
Source build sandbox	macOS Seatbelt / Linux bwrap+unshare, no network	macOS Seatbelt only, no Linux
Install manifests	Per-file SHA256 snapshot at install time	None
Lockfile	Full dependency tree with hashes	None
Integrity check	grew verify + grew doctor snapshot check	None
HTTPS enforcement	At parse time — HTTP URLs rejected before download	At download time
Path traversal protection	Validated at cellar, linker, loader, and archive extraction layers	Partial
Shell injection prevention	POSIX shell quoting via shellescape for sandbox scripts; systemd ExecStart and launchd plist values properly escaped	N/A
Zip Slip protection	Symlink indirection attacks blocked during tar/zip extraction	Partial
Command argument hardening	-- end-of-options separator on all external commands (git, systemctl, launchctl, hdiutil, tar, etc.)	Not consistently applied

Gradual rollout: signature verification doesn't block installs until you add keys to etc/trusted-keys. Tap verification is opt-in via HOMEGREW_TAP_VERIFY. This lets you adopt security features incrementally.

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🗺️ Roadmap

Got ideas? Bugs? Grievances? → Open an issue

Hot takes on the list:

• SLSA provenance attestations for bottles
• Content-addressable bottle storage
• Windows support (one day, probably, maybe)

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🤝 Contributing

1. Fork it
2. Branch it (git checkout -b feature/your-cool-thing)
3. Commit it (git commit -m "Add the cool thing")
4. Push it (git push origin feature/your-cool-thing)
5. PR it

PRs welcome. Drama not so much.

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📄 License

No license file yet — add a LICENSE to clarify what others can and can't do with your code. (It's the responsible thing to do. We believe in you.)

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📬 Contact

• 🐛 Open an issue
• 🔗 Project on GitHub

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💛 Acknowledgments

• Best-README-Template — the scaffold beneath the scaffold
• Everyone who ever squinted at a wall of package manager output and thought "there has to be a better way"