How to use Google's repo tool on MS Windows OS?

A working repo tool for windows is available here: https://github.com/esrlabs/git-repo

It requires Python 3+ and git 1.7.2+

Btw, the original forked repo version seems pretty old, so it might not contain all current functionalities.

Yes, Google repo script can be compliant with Windows. Follow the steps below.

But before, as Borealid said repo as not been ported on Windows. repo (forall.py) uses fcntl that is not available on Windows (Unix only).

However there is Cygwin and its own python and git tools.

If git version from MSysGit project for you or if you love your git GUI that is based on MSysGit only, then follow the following steps. These steps ensure that Cygwin can create native NTFS symlinks. Else if the git from Cygwin is sufficient, you do not have to do it. But it is better as setting CYGWIN=winsymlinks:native tells Cygwin to use native NTFS symlinks instead of old Cygwin workaround.

1. Use Windows Vista or later (or switch to Linux)
2. Have Admin privileges
3. Dowload and install Cygwin (32 or 64 bits)
4. Select and install python and git (and gpg if you want) from Cygwin installer

5. Set CYGWIN=winsymlinks:native in your Cygwin shell:

   export CYGWIN=winsymlinks:native
   mkdir NEW_DIR
   cd    NEW_DIR
   repo init -u YOUR_URL
   repo sync -j 7
   

(see also my other post)

There is an alternative for whoever has a choice to work with an alternative to repo, it's called gclient.

See Google's depot tools:

gclient: Meta-checkout tool managing both subversion and git checkouts. It is similar to repo tool except that it works on Linux, OS X, and Windows and supports both svn and git. On the other hand, gclient doesn't integrate any code review functionality.