Development

Software development on Windows is always interesting. This page documents some platform-specific issues people have encountered, and ways to resolve them.

Python

Windows 10 “helpfully” redirects the “python” executable in PATH to its bundled one, instead of any you may have installed separately (such as the one provided by Visual Studio). This breaks many python scripts.

To fix this:

• Type “App execution aliases” into the start bar and open the aliasing settings
• Disable aliasing for python and python3
• Remove %USERPROFILE%\AppData\Local\Microsoft\WindowsApps from your user-specific PATH if present
• Ensure that the Python tools are accessible by PATH. Appropriately adjust the path to the right version.
  • C:\Program Files (x86)\Microsoft Visual Studio\Shared\Python37_64 for python itself
  • C:\Program Files (x86)\Microsoft Visual Studio\Shared\Python37_64\Scripts for pip

Some Python scripts used by optional features of specregex require the pyyaml python pacakge to be installed. Running pip install pyyaml in the appropriate environment will achieve this.

Git Bash

• Download the latest version here and install git-bash, bash shell with git support for Windows
• Ensure that C:\Program Files\Git has been added to PATH (git-bash.exe lives here)
• Ensure that C:\Program Files\Git\cmd has been added to PATH (git.exe lives here)

Your home directory defaults to C:\Users\<Your name here>\.

CMake

CMake works the same on Windows as it does on Linux.

• Download the latest version here and install
• Ensure that C:\Program Files\CMake\bin has been added to PATH. The installer has a tick-box to do this for you, but any open shells must be re-started to see the changes.
• Remove or disable link.exe installed by Git from /Git/usr/bin/link.exe, since it name-collides with the Windows linker. It is not straightforward to ensure that the Windows one always appears first in PATH, so we suggest just deleting link.exe (which is not a linker).
  • Note that using lld-link.exe is not a viable workaround because it discards Windows debug information.
  • Note also that link.exe is not a dependency of ln, so this does not hinder the creation of symlinks.

Spectral LLVM

Make sure the /bin folder can be found in PATH.

Ninja

If you choose to use the Ninja cmake generator, do not use versions later than 1.10.0. They introduce an as-yet-unfixed bug that causes it to crash in some circumstances.

Instead, either: - Use the JOM CMake generator. It’s functionally equivalent to GNU make on Linux, so may feel familiar to users with experience there. - Use the Visual Studio CMake generator - Use Ninja 1.9.0