CMake Error when using component DD4hepPlugin but not TGeoPlugin (was ACTS-230)

Original author Valentin Volkl @vavolkl

find_package(ACTS COMPONENTS Core DD4hepPlugin REQUIRED) results in the error below. It works fine with find_package(ACTS COMPONENTS Core TGeoPlugin DD4hepPlugin REQUIRED). Maybe this is impractical to fix, but it could then perhaps be mentioned in the cmake setup instructions?

===================================================== Found package configuration file:

/afs/cern.ch/user/v/vavolkl/a-common-tracking-sw/install/share/cmake/ACTS/ACTSConfig.cmake

but it set ACTS_FOUND to FALSE so package "ACTS" is considered to be NOT FOUND. Reason given by package:

The following imported targets are referenced, but are missing: ACTS::ACTSTGeoPlugin