Reproducing a luban project on another machine

A Luban project committed to git can be rebuilt anywhere by anyone — even on machines that don't have luban installed. This is a property of the design (see Architecture → Design philosophy §3), not an afterthought.

Three scenarios

A. Target machine has luban

git clone <repo>
cd <repo>
luban build       # vcpkg fetches deps via manifest mode at the pinned baseline

Same fmt version, same toolchain, same binary semantics. Done.

B. Target machine has cmake + vcpkg, but no luban

git clone <repo>
cd <repo>
set VCPKG_ROOT=C:\path\to\vcpkg
cmake --preset default
cmake --build --preset default

Works. cmake includes the (committed) luban.cmake, vcpkg honors the (committed) vcpkg-configuration.json baseline. Same outputs.

This is why luban.cmake is git-tracked — it makes luban an optional convenience, not a build-time dependency.

C. Bare machine

:: install luban (one binary, one URL):
curl -O https://luban.coh1e.com/luban.exe

luban setup
luban env --user
:: open fresh shell

git clone <repo>
cd <repo>
luban build

What's pinned, what isn't

Concern	Pinned by	Lockfile-equivalent
Toolchain (cmake, ninja, clang)	`luban.exe` version on the target machine	luban release version
vcpkg ports baseline	`vcpkg-configuration.json` `baseline` field (commit SHA of microsoft/vcpkg)	yes
Per-port version	optional `dependencies[].version>=` + `overrides[]`	yes
Source code	git	yes
Generated cmake (`luban.cmake`)	git	yes (it's just text, regenerable but committed)

Best practices

Don't .gitignore luban.cmake — it's the bridge that makes "no-luban" reproducibility possible.
Pin a vcpkg baseline. luban new does this for you (uses the latest at scaffold time). Bump it intentionally with luban sync --baseline-now (M3) or by hand-editing vcpkg-configuration.json.
Document the toolchain. A README.md line like "Built with luban X.Y.Z (LLVM-MinGW 22, cmake 4.3+)" helps future-you and contributors.
Keep vcpkg.json minimal. Add only what you need. Each luban add should correspond to a real #include in your code — vcpkg builds everything in the manifest, so unused deps are time tax on every clean build.

Cross-platform reproducibility (future)

Today luban runs Windows-only. When the Linux/macOS port lands, the same vcpkg manifest will resolve different triplets (x64-linux, arm64-osx etc.). Project-level vcpkg.json doesn't change; only VCPKG_TARGET_TRIPLET differs in CMakePresets.json.

The Luban Book