site/docs/install-compile-source.md

---
layout: documentation
title: Compiling Bazel from Source
---

# <a name="compiling-from-source"></a>Compiling Bazel from Source (bootstrapping)

You can build Bazel from source without using an existing Bazel binary by
doing the following:

### 1.  Ensure that JDK 8, Python, Bash, zip, and the usual C++ build toolchain are installed on your system.

*   On systems based on Debian packages (Debian, Ubuntu): you can install
OpenJDK 8 and Python by running the following command in a terminal:

```sh
   sudo apt-get install build-essential openjdk-8-jdk python zip
```
*   On Windows: you need additional software and the right OS version.
See the [Windows page](windows.html).

### 2.  Download and unpack Bazel's distribution archive.

Download `bazel-<version>-dist.zip` from the [release page](https://github.com/bazelbuild/bazel/releases).

**Note:** There is a **single, architecture-independent** distribution archive. There are no architecture-specific or OS-specific distribution archives.

We recommend to also verify the signature made by our [release key](https://bazel.build/bazel-release.pub.gpg) 48457EE0.

The distribution archive contains generated files in addition to the versioned sources, so this step _cannot_ be short cut by checking out the source tree.

### 3.  Build Bazel using `./compile.sh`.
*   On Unix-like systems (e.g. Ubuntu, macOS), do the following steps in a shell session:
    1.  `cd` into the directory where you unpacked the distribution archive
    2.  run `bash ./compile.sh`
*   On Windows, do following steps in the MSYS2 shell:
    1.  `cd` into the directory where you unpacked the distribution archive
    2.  run `./compile.sh`

Once you have a Bazel binary, you no longer need to use the MSYS2 shell.
You can run Bazel from the Command Prompt (`cmd.exe`) or PowerShell.

The output will be `output/bazel` on Unix-like systems (e.g. Ubuntu, macOS)
and `output/bazel.exe` on Windows. This is a self-contained Bazel binary.
You can copy it to a directory on the `PATH` (such as `/usr/local/bin` on
Linux) or use it in-place.

### (on Windows): set the `JAVA_HOME` environment variable to the JDK's directory.

For example in the Windows Command Prompt (`cmd.exe`):

```
set JAVA_HOME=C:\Program Files\Java\jdk1.8.0_112
```

**Note**: do not use quotes (") around the path like you would on Unix.
Windows doesn't need them and they may confuse Bazel.

This step is not required if you downloaded a binary distribution of Bazel
or installed Bazel using Chocolatey. See [installing Bazel on
Windows](install-windows.html).