You'll need the following dependencies:
- libgranite-7-dev
- gtk4
- libvte-2.91-dev
- meson
- valac
Run meson to configure the build environment and then ninja test to build and run tests
meson build --prefix=/usr
cd build
ninja test
To install, use ninja install, then execute with /usr/libexec/xdg-desktop-portal-pantheon -r
sudo ninja install
/usr/libexec/xdg-desktop-portal-pantheon -r