Type of the currently used scheme. Only one type should be set to 1, other types should have empty values. Next table describe the difference between them:

  name <pkg>_ROOT EP? [1] cache [2]
HUNTER_PACKAGE_SCHEME_DOWNLOAD url_sha1_download source directory no yes
HUNTER_PACKAGE_SCHEME_UNPACK url_sha1_unpack source directory yes yes
HUNTER_PACKAGE_SCHEME_UNPACK_INSTALL url_sha1_unpack_install or url_sha1_unpack_bin_install install directory yes yes
HUNTER_PACKAGE_SCHEME_INSTALL other install directory yes no
[1]Does scheme use ExternalProject_Add? (information used while doing look up for stamps)
[2]Is package cacheable by default? Yes - always cacheable, No - depends on the package (see hunter_cacheable)