It has been mentioned in the comments of the older version of this article that the build process no longer works so I’ve decided, instead of updating old article, to write a new one.

Reason for the failed build is the fact that the build requirements changed, as well as the build commands.

It seems that for building the theme, PopOS crew transitioned to using Meson.

Let’s first install all of the requirements:

sudo dnf install glib2-devel sassc meson

Generate the theme files

meson build
cd build

Finally, install the theme:

ninja install

This will place it in global directory /usr/share/themes/.