USE_SYSTEM_BZIP2 should default to OFF when USE_SYSTEM_LIBARCHIVE is ON
In case system libarchive is enabled, the configure process reports
-- Using system-installed BZIP2
although it is not checked for or used. Supported compression methods depend on libarchive compile time options only.
Dito for zstd and liblzma and zlib.
(for zlib, the default should be ${CMAKE_USE_SYSTEM_CURL})
This issue is mostly cosmetical, as it only affects the messages, not the actually used options.
Edited by Brad King