These dependent packages should be installed.
sudo apt install libwebp-dev libgdk-pixbuf2.0-dev libgtk-3-dev meson build-essentialthen, build and install like this.
git clone https://github.com/aruiz/webp-pixbuf-loadercd webp-pixbuf-loader/meson builddir -Dgdk_pixbuf_query_loaders_path=/usr/lib/x86_64-linux-gnu/gdk-pixbuf-2.0/gdk-pixbuf-query-loadersninja -C builddirsudo ninja -C builddir install