How to install Qt5ThemeSupport on Ubuntu?

[locness3]

Trying to build QGnomePlatform on Ubuntu 21.10 aarch64 , running cmake .. says it can't find Qt5ThemeSupport:

CMake Error at CMakeLists.txt:43 (find_package):
  By not providing "FindQt5ThemeSupport.cmake" in CMAKE_MODULE_PATH this
  project has asked CMake to find a package configuration file provided by
  "Qt5ThemeSupport", but CMake did not find one.

  Could not find a package configuration file provided by "Qt5ThemeSupport"
  with any of the following names:

    Qt5ThemeSupportConfig.cmake
    qt5themesupport-config.cmake

  Add the installation prefix of "Qt5ThemeSupport" to CMAKE_PREFIX_PATH or
  set "Qt5ThemeSupport_DIR" to a directory containing one of the above files.
  If "Qt5ThemeSupport" provides a separate development package or SDK, be
  sure it has been installed.

I couldn't find anything related in the ubuntu packages. A google search seems to say I could use the qtbase5-private-dev package. However, trying to install this package, apt wants to remove most of my desktop environement(s) and apps (pastebin).

What's the proper way, if any, to install Qt5ThemeSupport on ubuntu to build this?

[grulja]

Hi, I will not be able to help with Ubuntu packages, but I think you are correct with the package you need to install.

[locness3]

but I think you are correct with the package you need to install.

Yeah, but I don't want to have my entire desktop deleted :)