Where to get xlocale.h?

I’m trying to get my company’s Python environment running. The install script uses Python virtualenvs to install the Python dependencies. Unfortunately, some packages need to be compiled (for instance Numpy) and so the script is running gcc commands. I have a shell.nix file where I’m installing the dependencies of the Python packages and then running the provided installer script. This fails, because gcc doesn’t find xlocale.h. I discovered, that on Fedora the fix was to symlink sudo ln -s /usr/include/locale.h /usr/include/xlocale.h. What do I need to include to the buildInputs of the mkShell command to achieve the same effect on NixOS?

which package is this?

I guess xlocale.h was meant to be an internal header for glibc, and was removed in 2.26.

you will probably have to make a nix expression for the package you want to build and do something simliar to https://github.com/NixOS/nixpkgs/blob/bc3fade573c8bfd49916b4afa3d00b37afe655ec/pkgs/development/libraries/icu/base.nix#L23