Windows 10 Arcanist Installation Guide

The official Windows installation guide for Arcanist is a bit confusing and vague. Here are step-by-step instructions to getting Arcanist working on Windows 10 in a MozillaBuild environment. They should work for Git Bash and PowerShell as well.

  1. Install the Microsoft Visual C++ 2015-2019 Redistributable (x64) if you don’t already have it. You can see if you have it through Settings -> Apps -> App & features. It is available at (vc_redist.x64.exe).

  2. Install PHP. The latest should work, e.g. PHP 7.2, VC15 x64 Non Thread Safe, from Download the Zip. Unzip it somewhere; the following instructions presume C:\PHP.

  3. Copy php.ini-development to php.ini in that same directory.

  4. Edit php.ini. The Arcanist docs say to remove the leading ; before ;extension=php_curl.dll. In PHP 7.2, this line is just ;extension=curl. Then find the line ;extension_dir = "ext" and change it to extension_dir = "C:\PHP\ext".

  5. Run C:\PHP\php.exe -i to verify that it is working. You should see “curl” listed in the Configuration section.

  6. If you don’t have Git already installed (note that it is not currently packaged with MozillaBuild), you’ll need to grab it from and install it.

  7. Clone the libphutil and arcanist Git repositories somewhere. These docs presume a subdirectory, phabricator, in your home directory, e.g. C:\Users\myuser\phabricator.

    mkdir phabricator
    cd phabricator
    git clone
    git clone

    Replace the last URL with if you are using git-cinnabar.

  8. Add arc and php to your user’s path. If you use MSYS (including MozillaBuild) exclusively, you can add this to ~/.bash_profile:

    export PATH="${PATH}:/c/php:${HOME}/phabricator/arcanist/bin"

    If you don’t have .bash_profile file on your system, you can create a blank text file named .bash_profile in your user folder: C:\Users\<username>\.

    You can also add it to your user’s path so that it is also recognized in PowerShell and other apps. The easiest way to find this setting is to type “environment variables” into the search bar at the bottom of the desktop, and select “Edit environment variables for your account”. You can also get to it via the Control Panel > All Control Panel Items > System > Advanced System Settings > Environment Variables…

    1. Select the “Path” variable under “User variables for <user>”.
    2. Click “Edit…”
    3. Click “New”
    4. Add C:\PHP
    5. Click “New”
    6. Add %USERPROFILE%\phabricator\arcanist\bin
  9. Verify this all works with arc help. You should see Arcanist’s usage instructions.

  10. Ensure you have an editor installed that has a “blocking mode” (not Notepad). MozillaBuild comes with vim, but there are other options, including Notepad++ and Sublime.

  11. Tell Arcanist about your editor:

    1. If you only use MSYS/MozillaBuild, you can just add export EDITOR=/usr/bin/vim to your .bash_profile.

    2. If you want to use vim but also want it available elsewhere (e.g. PowerShell), run

      arc set-config editor "\"C:\Program Files\Git\usr\bin\vim.exe\""
    3. If you’d like to use another editor, replace the path in the above command with the path to that editor. For some editors, you may need other command line options, e.g.

      • Notepad++:
      arc set-config editor "\"C:\Program Files (x86)\Notepad++\notepad++.exe\" -multiInst -nosession"
      • Sublime Text 2:
      arc set-config editor "\"C:\Program Files\Sublime Text 2\sublime_text.exe\" -w -n"
      • Sublime Text 3:
      arc set-config editor "\"C:\Program Files\Sublime Text 3\subl.exe\" -w -n"
  12. At this point, you should be all set up. Follow the rest of the standard instructions for configuring Arcanist to use our instance.