clonetree

README

Clonetree

Snapshot any directory using copy-on-write filesystem clones.

go install github.com/sprisa/clonetree@latest

# From the directory you want to snapshot:
clonetree init
clonetree new my-feature  # creates ./clonetree/my-feature.clonetree/
clonetree info
clonetree delete my-feature

# Choose a different snapshot parent directory:
clonetree new --dir ../snapshots my-feature
clonetree info --dir ../snapshots
clonetree delete --dir ../snapshots my-feature

# Explicitly disable live progress, including in a pseudo-terminal:
clonetree new --no-progress my-feature

• The source is always the current directory; no repository is required.
• init creates or updates .gitignore here with *.clonetree/.
• new <id> creates clonetree/<id>.clonetree/, including hidden files, ignored files, dependencies, and any .git or .sl metadata.
• --dir / -d changes the snapshot parent for new, info, and delete; relative paths are resolved from the current directory. Use --dir . to put snapshots here directly.
• Directories ending in .clonetree are skipped at every depth, including the destination itself.
• Reports clone time and estimated additional disk usage.
• Live progress is enabled by default when stderr is a TTY; --no-progress explicitly disables it.
• Interactive cloning counts entries first, then shows a percentage bar, entries/second, and estimated time remaining. Non-TTY and disabled runs skip that counting pass and keep output plain.
• Added disk usage is a filesystem free-space estimate; other activity and delayed accounting can affect it.
• info lists snapshots in the selected directory with live logical sizes and private storage where available (APFS); n/a means unavailable.
• Private storage excludes shared blocks and filesystem-wide metadata overhead.
• Files share storage until either checkout changes. Old data stays allocated while any clone needs it; a clone's private usage can grow when the original changes or is deleted.
• Uses native APFS clones on macOS and XFS/Btrfs reflinks on Linux; no full-copy fallback. Ext4 is unsupported.
• macOS reads metadata in native batches with reusable buffers; standard metadata reads handle unsupported filesystems and exceptional entries.
• Requires Go 1.24+ to install.
• Preserves permissions, modification times, and symlink targets. Stop writers while cloning; snapshots are not atomic.
• VCS metadata is copied as-is, including lock files. External stores and absolute paths retain their references.
• A cloned subdirectory is not automatically a new checkout; Git/Sapling can still discover the original parent repository.
• Run clonetree --help or clonetree <command> --help for details.
• Licensed under MPL-2.0.

Benchmark

Two non-interactive full-checkout runs on an Apple M4 Max with 128 GiB RAM, macOS 27.0.1, and APFS.

Metric	Result
Checkout size, including dependencies, Git metadata, and ignored files	39.2 GiB
Average clone time	55.0s
Individual runs	53.8s / 56.2s
Additional disk usage (free-space estimate)	~88–93 MiB
Regular files	~223,000
Directories	~36,700
Symlinks	~14,000
Source files (cloc)	2,587
Total source lines, including comments and blanks	627,040
Lines of code	518,265

Copy-on-write shares existing data blocks; additional space grows as files change. Timings and space estimates vary with filesystem state and other disk activity.

See performance notes for allocation benchmarks, escape-analysis findings, and collection-disabled memory measurements.

See testing for native XFS/Btrfs e2e tests in Ubuntu Docker or a VM, and APFS tests on a macOS host.

Releasing

• Set the release version in version.txt; it is embedded in the CLI.
• task build builds Go archives/checksums and npm packages. npm's JSON version is synchronized from version.txt before building or publishing.
• task release builds the archives, publishes npm packages, and creates the GitHub release with the archives and checksums attached.