https://bugzilla.gnome.org/show_bug.cgi?id=796655
Don't assume that meson is always a python script, on Windows it can be (and soon will almost always be) an executable. See: Meson MSI installer and https://github.com/mesonbuild/meson/pull/4004
https://bugzilla.gnome.org/show_bug.cgi?id=794519