Build an existing project

This page shows how to build a project that already has its ecosystem's manifest, such as a Cargo.toml, a go.mod or a CMakeLists.txt, without changing that manifest.

reprobuild reads the manifest for the project's structure and dependencies (Mode 2). You add a project file that names the package and the tools it uses.

Before you start

Install reprobuild.
The project follows its ecosystem's standard layout.
The tools named in the project file below are on your PATH, or you choose another source for them with --tool-provisioning.

Steps

1. Create the project file

In the directory that holds the manifest, create repro.nim. Name one package, the tools it uses, and the program or library it produces:

import repro_project_dsl

package rust_binary_example:
  uses:
    "rustc >=1.80 <2.0"
    "cargo >=1.80 <2.0"

  executable rust_binary_example:
    discard

import repro_project_dsl

package goBinaryExample:
  uses:
    "go >=1.22 <2.0"

  executable go_binary_example:
    discard

import repro_project_dsl

package c_cpp_cmake_hello_binary_example:
  uses:
    "gcc >=11"
    "cmake >=3.20"

  executable hello:
    discard

The uses: lines are version ranges. Use the ranges your project supports.

2. Check what reprobuild inferred

Check what reprobuild inferred from the manifest:

repro show-conventions

3. Build

Build:

repro build --tool-provisioning=path

--tool-provisioning=path uses the tools on your PATH. To let reprobuild provide them instead, choose another source, such as --tool-provisioning=nix.

Check that it worked

Run the build a second time. Nothing has changed, so reprobuild reuses every result and runs no compiler.

If the build does not match your manifest

Run repro show-conventions again and compare its targets with your manifest. The convention reads only the standard layout.
For a target that fits no convention, add a build: block to that target in repro.nim. The rest of the project stays on the convention.