site/docs/install-windows.md - bazel - Git at Google

 ---
 layout: documentation
 title: Installing Bazel on Windows
 ---

 # Installing Bazel on Windows

 ## Installing

 ### Step 1: Check your system

 Recommended: 64 bit Windows 10, version 1703 (Creators Update) or newer, enable "Developer Mode".

 <!-- Developer mode: for symlink support. -->

 Also supported:

 *   64 bit Windows 7 or newer

 *   64 bit Windows Server 2008 R2 or newer

 *   Older Windows 10 versions, disabled "Developer Mode" (enabling the mode just lets you use the
     `--enable_runfiles` Bazel flag)

 ### Step 2: Install the prerequisites

 *   [Visual C++ Redistributable for Visual Studio 2015](https://www.microsoft.com/en-us/download/details.aspx?id=48145)

 ### Step 3: Download Bazel

 [Download the Bazel binary (<code>bazel-&lt;version&gt;-windows-x86_64.exe</code>) from
  GitHub](https://github.com/bazelbuild/bazel/releases).

 Recommended: rename this binary to `bazel.exe` and move it to a directory on the `PATH`.

 Alternatively you can:

 *   [Download Bazelisk](https://github.com/bazelbuild/bazelisk) instead of Bazel. Bazelisk is a
     Bazel launcher that ensures you always use the latest Bazel release.
 *   [Install Bazel from Chocolatey](#using-chocolatey)
 *   [Install Bazel from Scoop](#using-scoop)
 *   [Build Bazel from source](install-compile-source.html)

 ### Step 4 (optional): Configure output directories

 **You can skip this step. Bazel can work without configuring the output directories, and will use
 its default values.**

 By default, Bazel writes to two directories:

 -   The "output user root", configurable with the `--output_user_root` flag.

     This is where Bazel extracts from itself its embedded tools, its own runtime, and where it
     writes some log files and some caches.

     This is also the default location for the "output base".

 -   The "output base", configurable with the `--output_base` flag.

     This is where Bazel writes all output files. By default, this is a subdirectory of the "output
     user root".

 By default, Bazel also writes in the workspace directory:

 -   The "convenience symlinks", configurable with the `--symlink_prefix` flag.

     These are the "bazel-bin", "bazel-testlogs", and similar directories that Bazel creates in your
     workspace. These are not really directories but "junctions": they just point to other
     directories in your filesystem (under the "output root").

     You can tell Bazel not to create these junctions with `--symlink_prefix=/`.

 ### Step 5 (optional): Install compilers and language runtimes

 **You can skip this step. Bazel can work without these programs, but you may need them.**

 We recommend installing:

 *   [MSYS2 x86_64](https://www.msys2.org/)

     MSYS2 is a software distro and building platform for Windows. It contains Bash and common Unix
     tools (like `grep`, `tar`, `git`).

     You will need MSYS2 to build, test, or run targets that depend on Bash. Typically these are
     `genrule`, `sh_binary`, `sh_test`, but there may be more (e.g. Starlark rules). Bazel shows an
     error if a build target needs Bash but Bazel could not locate it.

 *   Common MSYS2 packages

     You will likely need these to build and run targets that depend on Bash.  MSYS2 does not install
     these tools by default, so you need to install them manually. Projects that depend on Bash tools in `PATH` need this step (for example TensorFlow).

     Open the MSYS2 terminal and run this command:

     ```
     pacman -S zip unzip patch diffutils git
     ```
     Optional: If you want to use Bazel from CMD or Powershell and still be able to use Bash tools, make sure to add MSYS2_INSTALL_PATH/usr/bin to your PATH environment variable.

 *   [Build Tools for Visual Studio 2019](https://aka.ms/buildtools)

     Make sure you install the C++ build tools with the Windows 10 SDK.

     You will need this to build C++ code on Windows.

     Also supported:

     *   Visual Studio 2015 (or newer) with Visual C++ and Windows 10 SDK

     *   Visual C++ Build Tools 2015 (or newer) and Windows 10 SDK

 *   Java SE Development Kit 10 (JDK) for Windows x64

     You will need this to build Java code on Windows.

     Also supported: Java 8 and 9

 *   [Python 2.7 for Windows x86-64](https://www.python.org/downloads/windows/)

     You will need this to build Python code on Windows.

     Also supported: Python 3 or newer for Windows x86-64

 ### Step 6: Done

 **You have successfully installed Bazel.**

 Troubleshooting: see [troubleshooting](#troubleshooting) below.

 Tutorials: see [Getting Started with Bazel](getting-started.html) >
 [Tutorials](getting-started.html#tutorials).

 ---

 ## Troubleshooting

 ### Bazel does not find Bash or bash.exe

 **Possible reasons**:

 *   you installed MSYS2 not under the default install path

 *   you installed MSYS2 i686 instead of MSYS2 x86\_64

 *   you installed MSYS instead of MSYS2

 **Solution**:

 Ensure you installed MSYS2 x86\_64.

 If that doesn't help:

 1.  Go to Start Menu &gt; Settings.

 2.  Find the setting "Edit environment variables for your account"

 3.  Look at the list on the top ("User variables for &lt;username&gt;"), and click the "New..."
     button below it.

 4.  For "Variable name", enter `BAZEL_SH`

 5.  Click "Browse File..."

 6.  Navigate to the MSYS2 directory, then to `usr\bin` below it.

     For example, this might be `C:\msys64\usr\bin` on your system.

 7.  Select the `bash.exe` or `bash` file and click OK

 8.  The "Variable value" field now has the path to `bash.exe`. Click OK to close the window.

 9.  Done.

     If you open a new cmd.exe or PowerShell terminal and run Bazel now, it will find Bash.

 ### Bazel does not find Visual Studio or Visual C++

 **Possible reasons**:

 *   you installed multiple versions of Visual Studio

 *   you installed and removed various versions of Visual Studio

 *   you installed various versions of the Windows SDK

 *   you installed Visual Studio not under the default install path

 **Solution**:

 1.  Go to Start Menu &gt; Settings.

 2.  Find the setting "Edit environment variables for your account"

 3.  Look at the list on the top ("User variables for &lt;username&gt;"), and click the "New..."
     button below it.

 4.  For "Variable name", enter `BAZEL_VC`

 5.  Click "Browse Directory..."

 6.  Navigate to the `VC` directory of Visual Studio.

     For example, this might be `C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\VC`
     on your system.

 7.  Select the `VC` folder and click OK

 8.  The "Variable value" field now has the path to `VC`. Click OK to close the window.

 9.  Done.

     If you open a new cmd.exe or PowerShell terminal and run Bazel now, it will find Visual C++.

 ## Other ways to install Bazel

 ### Using Chocolatey

 1.  Install the [Chocolatey](https://chocolatey.org) package manager

 2.  Install the Bazel package:

         choco install bazel

     This command will install the latest available version of Bazel and
     its dependencies, such as the MSYS2 shell. This will not install Visual C++
     though.

 See [Chocolatey installation and package maintenance
 guide](https://bazel.build/windows-chocolatey-maintenance.html) for more
 information about the Chocolatey package.

 ### Using Scoop

 1.  Install the [Scoop](https://scoop.sh/) package manager using the following PowerShell command:

         iex (new-object net.webclient).downloadstring('https://get.scoop.sh')

 2.  Install the Bazel package:

         scoop install bazel

 See [Scoop installation and package maintenance
 guide](https://bazel.build/windows-scoop-maintenance.html) for more
 information about the Scoop package.

 ### Build from source

 See [here](install-compile-source.html).
	---
	layout: documentation
	title: Installing Bazel on Windows
	---

	# Installing Bazel on Windows

	## Installing

	### Step 1: Check your system

	Recommended: 64 bit Windows 10, version 1703 (Creators Update) or newer, enable "Developer Mode".

	<!-- Developer mode: for symlink support. -->

	Also supported:

	* 64 bit Windows 7 or newer

	* 64 bit Windows Server 2008 R2 or newer

	* Older Windows 10 versions, disabled "Developer Mode" (enabling the mode just lets you use the
	`--enable_runfiles` Bazel flag)

	### Step 2: Install the prerequisites

	* [Visual C++ Redistributable for Visual Studio 2015](https://www.microsoft.com/en-us/download/details.aspx?id=48145)

	### Step 3: Download Bazel

	[Download the Bazel binary (<code>bazel-<version>-windows-x86_64.exe</code>) from
	GitHub](https://github.com/bazelbuild/bazel/releases).

	Recommended: rename this binary to `bazel.exe` and move it to a directory on the `PATH`.

	Alternatively you can:

	* [Download Bazelisk](https://github.com/bazelbuild/bazelisk) instead of Bazel. Bazelisk is a
	Bazel launcher that ensures you always use the latest Bazel release.
	* [Install Bazel from Chocolatey](#using-chocolatey)
	* [Install Bazel from Scoop](#using-scoop)
	* [Build Bazel from source](install-compile-source.html)

	### Step 4 (optional): Configure output directories

	**You can skip this step. Bazel can work without configuring the output directories, and will use
	its default values.**

	By default, Bazel writes to two directories:

	- The "output user root", configurable with the `--output_user_root` flag.

	This is where Bazel extracts from itself its embedded tools, its own runtime, and where it
	writes some log files and some caches.

	This is also the default location for the "output base".

	- The "output base", configurable with the `--output_base` flag.

	This is where Bazel writes all output files. By default, this is a subdirectory of the "output
	user root".

	By default, Bazel also writes in the workspace directory:

	- The "convenience symlinks", configurable with the `--symlink_prefix` flag.

	These are the "bazel-bin", "bazel-testlogs", and similar directories that Bazel creates in your
	workspace. These are not really directories but "junctions": they just point to other
	directories in your filesystem (under the "output root").

	You can tell Bazel not to create these junctions with `--symlink_prefix=/`.

	### Step 5 (optional): Install compilers and language runtimes

	You can skip this step. Bazel can work without these programs, but you may need them.

	We recommend installing:

	* [MSYS2 x86_64](https://www.msys2.org/)

	MSYS2 is a software distro and building platform for Windows. It contains Bash and common Unix
	tools (like `grep`, `tar`, `git`).

	You will need MSYS2 to build, test, or run targets that depend on Bash. Typically these are
	`genrule`, `sh_binary`, `sh_test`, but there may be more (e.g. Starlark rules). Bazel shows an
	error if a build target needs Bash but Bazel could not locate it.

	* Common MSYS2 packages

	You will likely need these to build and run targets that depend on Bash. MSYS2 does not install
	these tools by default, so you need to install them manually. Projects that depend on Bash tools in `PATH` need this step (for example TensorFlow).

	Open the MSYS2 terminal and run this command:

	```
	pacman -S zip unzip patch diffutils git
	```
	Optional: If you want to use Bazel from CMD or Powershell and still be able to use Bash tools, make sure to add MSYS2_INSTALL_PATH/usr/bin to your PATH environment variable.

	* [Build Tools for Visual Studio 2019](https://aka.ms/buildtools)

	Make sure you install the C++ build tools with the Windows 10 SDK.

	You will need this to build C++ code on Windows.

	Also supported:

	* Visual Studio 2015 (or newer) with Visual C++ and Windows 10 SDK

	* Visual C++ Build Tools 2015 (or newer) and Windows 10 SDK

	* Java SE Development Kit 10 (JDK) for Windows x64

	You will need this to build Java code on Windows.

	Also supported: Java 8 and 9

	* [Python 2.7 for Windows x86-64](https://www.python.org/downloads/windows/)

	You will need this to build Python code on Windows.

	Also supported: Python 3 or newer for Windows x86-64

	### Step 6: Done

	You have successfully installed Bazel.

	Troubleshooting: see [troubleshooting](#troubleshooting) below.

	Tutorials: see [Getting Started with Bazel](getting-started.html) >
	[Tutorials](getting-started.html#tutorials).

	---

	## Troubleshooting

	### Bazel does not find Bash or bash.exe

	Possible reasons:

	* you installed MSYS2 not under the default install path

	* you installed MSYS2 i686 instead of MSYS2 x86\_64

	* you installed MSYS instead of MSYS2

	Solution:

	Ensure you installed MSYS2 x86\_64.

	If that doesn't help:

	1. Go to Start Menu > Settings.

	2. Find the setting "Edit environment variables for your account"

	3. Look at the list on the top ("User variables for <username>"), and click the "New..."
	button below it.

	4. For "Variable name", enter `BAZEL_SH`

	5. Click "Browse File..."

	6. Navigate to the MSYS2 directory, then to `usr\bin` below it.

	For example, this might be `C:\msys64\usr\bin` on your system.

	7. Select the `bash.exe` or `bash` file and click OK

	8. The "Variable value" field now has the path to `bash.exe`. Click OK to close the window.

	9. Done.

	If you open a new cmd.exe or PowerShell terminal and run Bazel now, it will find Bash.

	### Bazel does not find Visual Studio or Visual C++

	Possible reasons:

	* you installed multiple versions of Visual Studio

	* you installed and removed various versions of Visual Studio

	* you installed various versions of the Windows SDK

	* you installed Visual Studio not under the default install path

	Solution:

	1. Go to Start Menu > Settings.

	2. Find the setting "Edit environment variables for your account"

	3. Look at the list on the top ("User variables for <username>"), and click the "New..."
	button below it.

	4. For "Variable name", enter `BAZEL_VC`

	5. Click "Browse Directory..."

	6. Navigate to the `VC` directory of Visual Studio.

	For example, this might be `C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\VC`
	on your system.

	7. Select the `VC` folder and click OK

	8. The "Variable value" field now has the path to `VC`. Click OK to close the window.

	9. Done.

	If you open a new cmd.exe or PowerShell terminal and run Bazel now, it will find Visual C++.

	## Other ways to install Bazel

	### Using Chocolatey

	1. Install the [Chocolatey](https://chocolatey.org) package manager

	2. Install the Bazel package:

	choco install bazel

	This command will install the latest available version of Bazel and
	its dependencies, such as the MSYS2 shell. This will not install Visual C++
	though.

	See [Chocolatey installation and package maintenance
	guide](https://bazel.build/windows-chocolatey-maintenance.html) for more
	information about the Chocolatey package.

	### Using Scoop

	1. Install the [Scoop](https://scoop.sh/) package manager using the following PowerShell command:

	iex (new-object net.webclient).downloadstring('https://get.scoop.sh')

	2. Install the Bazel package:

	scoop install bazel

	See [Scoop installation and package maintenance
	guide](https://bazel.build/windows-scoop-maintenance.html) for more
	information about the Scoop package.

	### Build from source

	See [here](install-compile-source.html).