Windows installation

We outline the steps for installing MRtrix3 for Windows using MSYS2. Please consult the MRtrix3 forum if you encounter any issues with the configure, build or runtime operations of MRtrix3.

Warning

Some of the Python scripts provided with MRtrix3 are dependent on external software tools (for instance FSL). If these packages are not available on Windows, then the corresponding MRtrix3 scripts also cannot be run on Windows. A virtual machine may therefore be required in order to use these particular scripts; though MRtrix3 may still be installed natively on Windows for other tasks.

Check requirements

To install MRtrix3, you will need the following:

  • a C++11 compliant compiler
  • Python version >= 2.7
  • The zlib compression library
  • Eigen version >= 3.2
  • Qt version >= 4.7 [GUI components only]

Note

All of these dependencies are installed below by the MSYS2 package manager.

Warning

To run the GUI components of MRtrix3 (mrview & shview), you will also need:

  • an OpenGL 3.3 compliant graphics card and corresponding software driver

Warning

When following the instructions below, use the ‘MinGW-w64 Win64 shell’; ‘MSYS2 shell’ and ‘MinGW-w64 Win32 shell’ should be avoided.

Install and update MSYS2

  1. Download and install the most recent 64-bit MSYS2 installer from http://msys2.github.io/ (msys2-x86_64-*.exe), and following the installation instructions from the MSYS2 wiki.

  2. Run the program ‘MinGW-w64 Win64 Shell’ from the start menu.

  3. Update the system packages, as per the instructions:

    pacman -Syuu

    Close the terminal, start a new ‘MinGW-w64 Win64 Shell’, and repeat as necessary until no further packages are updated.

Warning

At time of writing, this MSYS2 system update will give a number of instructions, including: terminating the terminal when the update is completed, and modifying the shortcuts for executing the shell(s). Although these instructions are not as prominent as they could be, it is vital that they are followed correctly!

Install MRtrix3 dependencies

  1. From the ‘MinGW-w64 Win64 Shell’ run:

    pacman -S git python pkg-config mingw-w64-x86_64-gcc mingw-w64-x86_64-eigen3 mingw-w64-x86_64-qt5

    Sometimes pacman may fail to find a particular package from any of the available mirrors. If this occurs, you can download the relevant package from SourceForge: place both the package file and corresponding .sig file into the /var/cache/pacman/pkg directory, and repeat the pacman call above.

    Sometimes pacman may refuse to install a particular package, claiming e.g.:

    error: failed to commit transaction (conflicting files)
mingw-w64-x86_64-eigen3: /mingw64 exists in filesystem
Errors occurred, no packages were upgraded.

    Firstly, if the offending existing target is something trivial that can be deleted, this is all that should be required. Otherwise, it is possible that MSYS2 may mistake a _file_ existing on the filesystem as a pre-existing _directory_; a good example is that quoted above, where pacman claims that directory /mingw64 exists, but it is in fact the two files /mingw64.exe and /mingw64.ini that cause the issue. Temporarily renaming these two files, then changing their names back after pacman has completed the installation, should solve the problem.

Set up git and download MRtrix3 sources

  1. Configure global settings for Git in the ‘MinGW-w64 Win64 Shell’:

    git config --global user.name "John Doe"
git config --global user.email johndoe@example.com
git config --global push.default upstream

  2. Clone the MRtrix3 repository:

    git clone https://github.com/MRtrix3/mrtrix3.git

Build MRtrix3

  1. Configure the MRtrix3 install:

    cd mrtrix3
./configure

    If this does not work, examine the ‘configure.log’ file that is generated by this step, it may give clues as to what went wrong.

  2. Build the binaries:

    ./build

Set up MRtrix3

  1. Update the shell startup file, so that the shell can locate the MRtrix3 commands and scripts, by adding the bin/ folder to your PATH environment variable.

    If you are not familiar or comfortable with modification of shell files, MRtrix3 provides a convenience script that will perform this setup for you (assuming that you are using bash or equivalent interpreter). From the top level MRtrix3 directory, run the following:

    ./set_path

  2. Close the terminal and start another one to ensure the startup file is read (or just type ‘bash’)

  3. Type mrview to check that everything works

  4. You may also want to have a look through the List of MRtrix3 configuration file options and set anything you think might be required on your system.

Keeping MRtrix3 up to date

  1. You can update your installation at any time by typing:

    git pull
./build

  2. If this doesn’t work immediately, it may be that you need to re-run the configure script:

    ./configure

    and re-run step 1 again.

Compiling external projects with msys2

In msys2, the ln -s command actually creates a copy of the target, not a symbolic link. By doing so, the build script is unable to identify the location of the MRtrix libraries when trying to compile an external module.

The simplest way around this is simply to invoke the build script of the main MRtrix3 install directly. For example, if compiling an external project called myproject, residing in a folder alongside the main mrtrix3 folder, the build script can be invoked with:

# current working directory is 'myproject':
../mrtrix3/build

If you really want a symbolic link, one solution is to use a standard Windows command prompt, with Administrator privileges: In the file explorer, go to C:\Windows\system32, locate the file cmd.exe, right-click and select ‘Run as administrator’. Within this prompt, use the mklink command (note that the argument order passed to mklink is reversed with respect to ln -s; i.e. provide the location of the link, then the target). Make sure that you provide the full path to both link and target, e.g.:

mklink C:\msys64\home\username\src\my_project\build C:\msys64\home\username\src\MRtrix3\build

and msys64 should be able to interpret the softlink path correctly (confirm with ls -la).

I have also found recently that the build script will not correctly detect use of a softlink for compiling an external project when run under Python2, so Python3 must be used explicitly.