[retiredbiker]

Thanks for the quick replies.

I actually did follow the philja experience. This morning after some sleep and a reboot, I double-checked that the various packages in the philja thread were installed, and tried the configuration again. Now it seems to not complain about the files missing, but throws a completely new error:

Spoiler:

chris@pop-os:~/sigil-src$ cmake -G "Unix Makefiles" -DCMAKE_BUILD_TYPE=Release ../sigil-src
-- CMake version in use: 3.22.1
-- Using older findpython cmake module
-- Using Bundled ZLIB
-- Using Bundled MiniZip
-- Using Bundled Hunspell
-- Using Bundled PCRE2
CMake Warning at src/qt5sigil.cmake:34 (find_package):
By not providing "FindQt5.cmake" in CMAKE_MODULE_PATH this project has
asked CMake to find a package configuration file provided by "Qt5", but
CMake did not find one.

Could not find a package configuration file provided by "Qt5" (requested
version 5.10) with any of the following names:

Qt5Config.cmake
qt5-config.cmake

Add the installation prefix of "Qt5" to CMAKE_PREFIX_PATH or set "Qt5_DIR"
to a directory containing one of the above files. If "Qt5" provides a
separate development package or SDK, be sure it has been installed.
Call Stack (most recent call first):
src/CMakeLists.txt:674 (include)


CMake Error at src/qt5sigil.cmake:81 (qt5_wrap_ui):
Unknown CMake command "qt5_wrap_ui".
Call Stack (most recent call first):
src/CMakeLists.txt:674 (include)


-- Configuring incomplete, errors occurred!
See also "/home/chris/sigil-src/CMakeFiles/CMakeOutput.log".
See also "/home/chris/sigil-src/CMakeFiles/CMakeError.log".

Seems to suddenly be looking for qt5 things? I did try the qt5 command (cmake -G "Unix Makefiles" -DUSE_QT5=1 -DCMAKE_BUILD_TYPE=Release ../sigil-src) last night just to see if it would work - no - did that set something that is now getting in the way?