What should the DESTINATION be for a header only library's CMake config file?

[buildSystemPerson]

@craig.scott

For this, share/cmake/<packageName> may be more suitable.

Gotcha, looking at GNUInstallDirs that translates to: ${CMAKE_INSTALL_DATADIR}/cmake/<packageName>

DATAROOTDIR

read-only architecture-independent data root (share)

DATADIR

read-only architecture-independent data (DATAROOTDIR)