opentofu/BUILDING.md

# Building from Source

If you'd like to build OpenTofu from source, you can do so using the Go build toolchain and the options specified in this document.

## Prerequisites

1. Ensure you've installed the Go language version specified in [`.go-version`](.go-version).
2. Clone this repository to a location of your choice.

## OpenTofu Build Options

OpenTofu accepts certain options passed using `ldflags` at build time which control the behavior of the resulting binary.

### Dev Version Reporting

OpenTofu will include a `-dev` flag when reporting its own version (ex: 1.5.0-dev) unless `version.dev` is set to `no`:

```
go build -ldflags "-w -s -X 'github.com/opentofu/opentofu/version.dev=no'" -o bin/ ./cmd/tofu
```

### Experimental Features

Experimental features of OpenTofu will be disabled unless `main.experimentsAllowed` is set to `yes`:

```
go build -ldflags "-w -s -X 'main.experimentsAllowed=yes'" -o bin/ ./cmd/tofu
```

## Go Options

For the most part, the OpenTofu release process relies on the Go toolchain defaults for the target operating system and processor architecture.

### `CGO_ENABLED`

One exception is the `CGO_ENABLED` option, which is set explicitly when building OpenTofu binaries. For most platforms, we build with `CGO_ENABLED=0` in order to produce a statically linked binary. For MacOS/Darwin operating systems, we build with `CGO_ENABLED=1` to avoid a platform-specific issue with DNS resolution.