When installing rofi 1.6.1 from source on Ubuntu, there are some missing dependencies. To install those, enter this command:
sudo apt install libxcb-xkb-dev libxcb-ewmh-dev libxkbcommon-x11-dev libxcb-icccm4-dev libxcb-xinerama0-dev libxcb-xrm-dev build-essential cmake extra-cmake-modules xcb
The check version in the default repos is also outdated, so you need to compile that from source too.