would it be possible to extract an achive direct to the name cache dir?

[ClausKlein]

if(EXISTS "$ENV{CPM_SOURCE_CACHE}/boost_1_79_0")
  set(FETCHCONTENT_SOURCE_DIR_BOOST "$ENV{HOME}/.cache/CPM/boost_1_79_0" CACHE PATH "Boost source DIR")
  set(CPM_Boost_SOURCE ${FETCHCONTENT_SOURCE_DIR_BOOST} CACHE PATH "Manual override")
endif()

CPMAddPackage(
   NAME Boost
   VERSION 1.79.0
   URL https://boostorg.jfrog.io/artifactory/main/release/1.79.0/source/boost_1_79_0.tar.bz2
   URL_HASH SHA256=475d589d51a7f8b3ba2ba4eda022b170e562ca3b760ee922c146b6c65856ef39
   DOWNLOAD_ONLY True
)

At the moment, I have to move the cached dir manualy to FETCHCONTENT_SOURCE_DIR_BOOST

IMHO, CPM should check if the directory exists and perhaps if it contains a CMakeLists.txt file.
If not, a download to this directory should be done, or an ERROR should be shown.

see https://github.com/ClausKlein/boost-cmake/blob/feature/upgrade-to-boost-V1-79-0/CMakeLists.txt