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Julia on Windows

This file describes how to install, or build, and use Julia on Windows.

For more general information about Julia, please see the main README or the documentation.

General Information for Windows

Unicode font support

The built-in Windows fonts have rather poor coverage of the Unicode character space. The free DejaVu Sans Mono font can be used as a replacement font in the Windows console. Since Windows 2000, simply downloading the font and installing it is insufficient, since Windows keeps a list of approved fonts in the registry.

Instructions for adding fonts to the terminal are available at this answer on

Additionally, rather than sticking with the default command prompt, you may want to use a different terminal emulator program, such as Conemu or Mintty (note that running Julia on Mintty needs a copy of stty.exe in your %PATH% to work properly). Alternatively, you may prefer the features of a more full-function IDE, such as Juno, Sublime-IJulia, or IJulia.

Line endings

Julia uses binary-mode files exclusively. Unlike many other Windows programs, if you write \n to a file, you get a \n in the file, not some other bit pattern. This matches the behavior exhibited by other operating systems. If you have installed Git for Windows, it is suggested, but not required, that you configure your system Git to use the same convention:

git config --global core.eol lf
git config --global core.autocrlf input

or edit %USERPROFILE%\.gitconfig and add/edit the lines:

    eol = lf
    autocrlf = input

Binary distribution

Julia runs on Windows 7 and later. Both the 32-bit and 64-bit versions are supported. The 32-bit (i686) binary will run on either a 32-bit and 64-bit operating system. The 64-bit (x86_64) binary will only run on 64-bit Windows and will otherwise refuse to launch.

  1. Download the latest version of Julia. Extract the binary to a reasonable destination folder, e.g. C:\julia.

  2. Double-click the julia shortcut to launch Julia.

  3. Julia's home directory is the location pointed to by the Windows environment variable %HOME%: this directory is for instance where the startup file .julia/config/startup.jl resides. %HOMEDRIVE%\%HOMEPATH% is used as a fallback if %HOME% is not defined.

Source distribution

Supported build platforms

  • Windows 10: supported (32 and 64 bits)
  • Windows 8: supported (32 and 64 bits)
  • Windows 7: supported (32 and 64 bits)

Cygwin-to-MinGW cross-compiling

The recommended way of compiling Julia from source on Windows is by cross compiling from Cygwin, using versions of the MinGW-w64 compilers available through Cygwin's package manager.

  1. Download and run Cygwin setup for 32 bit or 64 bit. Note, that you can compile either 32 or 64 bit Julia from either 32 or 64 bit Cygwin. 64 bit Cygwin has a slightly smaller but often more up-to-date selection of packages.

    Advanced: you may skip steps 2-4 by running:

    setup-x86_64.exe -s <url> -q -P cmake,gcc-g++,git,make,patch,curl,m4,python,p7zip,mingw64-i686-gcc-g++,mingw64-i686-gcc-fortran,mingw64-x86_64-gcc-g++,mingw64-x86_64-gcc-fortran
    :: replace <url> with a site from
    :: or run setup manually first and select a mirror
  2. Select installation location and download mirror.

  3. At the 'Select Packages' step, select the following:

    1. From the Devel category: cmake, gcc-g++, git, make, patch
    2. From the Net category: curl
    3. From Interpreters (or Python) category: m4, python
    4. From the Archive category: p7zip
    5. For 32 bit Julia, and also from the Devel category: mingw64-i686-gcc-g++ and mingw64-i686-gcc-fortran
    6. For 64 bit Julia, and also from the Devel category: mingw64-x86_64-gcc-g++ and mingw64-x86_64-gcc-fortran
  4. At the 'Resolving Dependencies' step, be sure to leave 'Select required packages (RECOMMENDED)' enabled.

  5. Allow Cygwin installation to finish, then start from the installed shortcut a 'Cygwin Terminal', or 'Cygwin64 Terminal', respectively.

  6. Build Julia and its dependencies from source:

    1. Get the Julia sources

      git clone
      cd julia

      Tip: If you get an error: cannot fork() for fetch-pack: Resource temporarily unavailable from git, add alias git="env PATH=/usr/bin git" to ~/.bashrc and restart Cygwin.

    2. Set the XC_HOST variable in Make.user to indicate MinGW-w64 cross compilation

      echo 'XC_HOST = i686-w64-mingw32' > Make.user     # for 32 bit Julia
      # or
      echo 'XC_HOST = x86_64-w64-mingw32' > Make.user   # for 64 bit Julia
    3. Start the build

      make -j 4   # Adjust the number of cores (4) to match your build environment.

    Protip: build both!

    make O=julia-win32 configure
    make O=julia-win64 configure
    echo 'XC_HOST = i686-w64-mingw32' > julia-win32/Make.user
    echo 'XC_HOST = x86_64-w64-mingw32' > julia-win64/Make.user
    echo 'ifeq ($(BUILDROOT),$(JULIAHOME))
            $(error "in-tree build disabled")
          endif' >> Make.user
    make -C julia-win32  # build for Windows x86 in julia-win32 folder
    make -C julia-win64  # build for Windows x86-64 in julia-win64 folder
  7. Run Julia using the Julia executables directly


Compiling with MinGW/MSYS2

Compiling Julia from source using MSYS2 has worked in the past but is not actively supported. Pull requests to restore support would be welcome. See a past version of this file for the former instructions for compiling using MSYS2.

Cross-compiling from Unix

You can also use MinGW-w64 cross compilers to build a Windows version of Julia from Linux, Mac, or the Windows Subsystem for Linux (WSL). Note that when compiling in WSL, you should use the Linux file system environment, not the /mnt/ emulated Windows paths, since time stamps in /mnt/ do not work properly as required by configure scripts and makefiles (see

For maximum compatibility with packages that use WinRPM.jl for binary dependencies on Windows, it is recommended that you use OpenSUSE 42.2 for cross-compiling a Windows build of Julia. If you use a different Linux distribution or OS X, install Vagrant and use the following Vagrantfile:

# Vagrantfile for MinGW-w64 cross-compilation of Julia

$script = <<SCRIPT
# Change the following to i686-w64-mingw32 for 32 bit Julia:
export XC_HOST=x86_64-w64-mingw32
# Change the following to 32 for 32 bit Julia:
export BITS=64
zypper addrepo$BITS/openSUSE_Leap_42.2/windows:mingw:win$BITS.repo
zypper --gpg-auto-import-keys refresh
zypper -n install --no-recommends git make cmake tar wine which curl \
    python python-xml patch gcc-c++ m4 p7zip.i586 libxml2-tools winbind
zypper -n install mingw$BITS-cross-gcc-c++ mingw$BITS-cross-gcc-fortran \
    mingw$BITS-libstdc++6 mingw$BITS-libgfortran3 mingw$BITS-libssp0
# opensuse packages the mingw runtime dlls under sys-root/mingw/bin, not /usr/lib64/gcc
cp /usr/$XC_HOST/sys-root/mingw/bin/*.dll /usr/lib*/gcc/$XC_HOST/*/
git clone git:// julia
cd julia
make -j4 win-extras julia-ui-release
export WINEDEBUG=-all # suppress wine fixme's
# this last step may need to be run interactively
make -j4 binary-dist

Vagrant.configure("2") do |config| = "bento/opensuse-leap-42.2"
  config.vm.provider :virtualbox do |vb|
    # Use VBoxManage to customize the VM. For example to change memory:
    vb.memory = 2048
  config.vm.provision :shell, :inline => $script

Cross-building Julia without Vagrant

If you don't care that the build is potentially incompatible with the WinRPM ecosystem (or happen to be on opensuse), use the following steps to cross- compile julia:

First, you will need to ensure your system has the required dependencies. We need wine (>=1.7.5), a system compiler, and some downloaders.

On Ubuntu (on other linux systems, the dependency names are likely to be similar):

apt-get install wine subversion cvs gcc wget p7zip-full winbind mingw-w64

On Mac: Install XCode, XCode command line tools, X11 (now XQuartz), and MacPorts or Homebrew. Then run port install wine wget mingw-w64, or brew install wine wget mingw-w64, as appropriate.

Then run the build:

  1. git clone julia-win32
  2. echo override XC_HOST = i686-w64-mingw32 >> Make.user
  3. make
  4. make win-extras (Necessary before running make binary-dist)
  5. make binary-dist
  6. move the julia-*.exe installer to the target machine

If you are building for 64-bit windows, the steps are essentially the same. Just replace i686 in XC_HOST with x86_64. (note: on Mac, wine only runs in 32-bit mode).

Debugging a cross-compiled build under wine

The most effective way to debug a cross-compiled version of julia on the cross- compilation host is to install a windows version of gdb and run it under wine as usual. The pre-built packages available as part of the MSYS2 project are known to work. Apart from the GDB package you may also need the python and termcap packages. Finally, GDB's prompt may not work when launch from the command line. This can be worked around by prepending wineconsole to the regular GDB invocation.

Using a Windows VM

Vagrant can also be used with a Windows guest VM via the Vagrantfile in contrib/windows, just run vagrant up from that folder.

After compiling

Compiling using one of the options above creates a basic Julia build, but not some extra components that are included if you run the full Julia binary installer. If you need these components, the easiest way to get them is to build the installer yourself using make win-extras followed by make binary-dist, and then running the resulting installer.

Windows Build Debugging

GDB hangs with cygwin mintty

  • Run gdb under the windows console (cmd) instead. gdb may not function properly under mintty with non- cygwin applications. You can use cmd /c start to start the windows console from mintty if necessary.

GDB not attaching to the right process

  • Use the PID from the windows task manager or WINPID from the ps command instead of the PID from unix style command line tools (e.g. pgrep). You may need to add the PID column if it is not shown by default in the windows task manager.

GDB not showing the right backtrace

  • When attaching to the julia process, GDB may not be attaching to the right thread. Use info threads command to show all the threads and thread <threadno> to switch threads.
  • Be sure to use a 32 bit version of GDB to debug a 32 bit build of Julia, or a 64 bit version of GDB to debug a 64 bit build of Julia.

Build process is slow/eats memory/hangs my computer

  • Disable the Windows Superfetch and Program Compatibility Assistant services, as they are known to have spurious interactions with MinGW/Cygwin.

    As mentioned in the link above: excessive memory use by svchost specifically may be investigated in the Task Manager by clicking on the high-memory svchost.exe process and selecting Go to Services. Disable child services one-by-one until a culprit is found.

  • Beware of BLODA. The vmmap tool is indispensable for identifying such software conflicts. Use vmmap to inspect the list of loaded DLLs for bash, mintty, or another persistent process used to drive the build. Essentially any DLL outside of the Windows System directory is potential BLODA.