bit

Git implementation in MoonBit - fully compatible with some extensions.

Warning: This is an experimental implementation. Do not use in production. Data corruption may occur in worst case scenarios. Always keep backups of important repositories.

Install

Supported platforms: Linux x64, macOS arm64/x64

# One-line install
curl -fsSL https://raw-githubusercontent-com-gh.computerqwq.top/mizchi/bit/main/install.sh | bash

# Or build from source
git clone https://github.com/mizchi/bit
cd bit
just install  # requires MoonBit toolchain

Installs to ~/.local/bin/bit.

Shell Completion

# bash (~/.bashrc)
eval "$(bit completion bash)"

# zsh (~/.zshrc)
eval "$(bit completion zsh)"

Subdirectory Clone

Clone subdirectories directly from GitHub:

# Using @user/repo/path shorthand
bit clone mizchi/bit:src/x/fs

# Or paste GitHub browser URL
bit clone https://github.com/user/repo/tree/main/packages/core

# Single file download
bit clone https://github.com/user/repo/blob/main/README.md

Cloned subdirectories have their own .git directory. When placed inside another git repository, git automatically treats them as embedded repositories (like submodules) - the parent repo won't commit their contents.

Standard Git Commands

bit clone https://github.com/user/repo
bit checkout -b feature
bit add .
bit commit -m "changes"
bit push origin feature

Compatibility

• Hash algorithm: SHA-1 only.
• SHA-256 repositories and --object-format=sha256 are not supported.
• Git config: reads global aliases from ~/.gitconfig (or GIT_CONFIG_GLOBAL) only.
• Shell aliases (prefixed with !) are not supported.

Git Test Suite (git/t)

706 test files from the official Git test suite are in the allowlist. Results on macOS:

	Count
success	24,278
failed	0
broken (prereq skip)	178
total	24,858

178 broken tests are skipped due to missing prerequisites, not failures:

Category	Prereqs	Skips	Notes
Platform	MINGW, WINDOWS, NATIVE_CRLF, SYMLINKS_WINDOWS	~72	Windows-only tests
GPG signing	GPG, GPG2, GPGSM, RFC1991	~127	brew install gnupg to enable
Terminal	TTY	~33	Requires interactive terminal
Build config	EXPENSIVE, BIT_SHA256, PCRE, HTTP2, SANITIZE_LEAK, RUNTIME_PREFIX	~30	Optional build/test flags
Filesystem	SETFACL, LONG_REF, TAR_HUGE, TAR_NEEDS_PAX_FALLBACK	~10	Platform-specific capabilities
Negative prereqs	!AUTOIDENT, !CASE_INSENSITIVE_FS, !LONG_IS_64BIT, !PTHREADS, !SYMLINKS	~7	Tests requiring feature absence

5 test files are excluded from the allowlist: t5310 (bitmap), t5316 (delta depth), t5317 (filter-objects), t5332 (multi-pack reuse), t5400 (send-pack).

Environment Variables

• BIT_BENCH_GIT_DIR: override .git path for bench_real (x/fs benchmarks).
• BIT_PACK_CACHE_LIMIT: max number of pack files to keep in memory (default: 2; 0 disables cache).
• BIT_RACY_GIT: when set, rehash even if stat matches to avoid racy-git false negatives.

Extensions

Fs - Virtual Filesystem

Mount any commit as a filesystem with lazy blob loading:

let fs = Fs::from_commit(fs, ".git", commit_id)
let files = fs.readdir(fs, "src")
let content = fs.read_file(fs, "src/main.mbt")

Kv - Distributed KV Store

Git-backed key-value store with Gossip protocol sync:

let db = Kv::init(fs, fs, git_dir, node_id)
db.set(fs, fs, "users/alice/profile", value, ts)
db.sync_with_peer(fs, fs, peer_url)

Collab - Git-Native Collaboration

Pull Requests and Issues stored as Git objects:

let collab = Collab::init(fs, fs, git_dir)
let pr = collab.create_pr(fs, fs, "Fix bug", "...",
  source_branch, target_branch, author, ts)

License

Apache-2.0