Stellarsolver is installed and the IDE reports:
(...)
-- Found INDI: /usr/lib/x86_64-linux-gnu/libindiclient.a, /usr/include/libindi
-- Checking for module 'stellarsolver'
-- Found stellarsolver, version 1.5
-- Found StellarSolver: /usr/local/lib/libstellarsolver.so
-- Found NOVA: /usr/lib/x86_64-linux-gnu/libnova.so
(...)
But the configuration of the project is broken:
This is the error message: Target "kstars" links to target "StellarSolver::stellarsolver" but the target was not found. Perhaps a find_package() call is missing for an IMPORTED target, or an ALIAS target is missing?
Could be a problem with cmake/modules/FindStellarSolver.cmake