CMake: redundant "lib"

[kmilos]

Since 4.5.0 there is a redundant "lib" directory created when installing some artifacts:

/lib/lib/cfitsio-4.5.0/
/lib/lib/cfitsio-4.5.0/cfitsio-config.cmake
/lib/lib/cfitsio-4.5.0/cfitsio-config-version.cmake
/lib/lib/pkgconfig/
/lib/lib/pkgconfig/cfitsio.pc

This seems to be regression introduced in 29eccbb trying to address #23.

Edit: Arch workaround, Fedora patch...

[kmilos]

Btw, there's seldom need to override and construct LIB_DESTINATION (and other install dirs) by hand like that.

GNUInstallDirs CMAKE_INSTALL_LIBDIR (and others) should be correct (almost) all the time, even on multi-arch systems.

[bryanirby]

Hi @kmilos, thanks for the report. I've checked a fix for this into the develop branch. We'll look into revising the use of LIB_DESTINATION et al. in future development.