--- Modules/Internal/CPack/CPackBSDSUniX.cmake.orig	2021-07-10 13:38:26 UTC
+++ Modules/Internal/CPack/CPackBSDSUniX.cmake
@@ -0,0 +1,107 @@
+# Distributed under the OSI-approved BSD 3-Clause License.  See accompanying
+# file Copyright.txt or https://cmake.org/licensing for details.
+
+
+if(CMAKE_BINARY_DIR)
+  message(FATAL_ERROR "CPackBSDSUniX.cmake may only be used by CPack internally.")
+endif()
+
+if(NOT UNIX)
+  message(FATAL_ERROR "CPackBSDSUniX.cmake may only be used under UNIX.")
+endif()
+
+
+###
+#
+# These bits are copied from the Debian packaging file; slightly modified.
+# They are used for filling in BSDSUniX-packaging variables that can take
+# on values from elsewhere -- e.g. the package description may as well be
+# copied from Debian.
+#
+function(_cpack_bsdsunix_fallback_var OUTPUT_VAR_NAME)
+  set(FALLBACK_VAR_NAMES ${ARGN})
+
+  set(VALUE "${${OUTPUT_VAR_NAME}}")
+  if(VALUE)
+    return()
+  endif()
+
+  foreach(variable_name IN LISTS FALLBACK_VAR_NAMES)
+    if(${variable_name})
+      set(${OUTPUT_VAR_NAME} "${${variable_name}}" PARENT_SCOPE)
+      set(VALUE "${${variable_name}}")
+      break()
+    endif()
+  endforeach()
+  if(NOT VALUE)
+    message(WARNING "Variable ${OUTPUT_VAR_NAME} could not be given a fallback value from (any of) ${FALLBACK_VAR_NAMES}.")
+  endif()
+endfunction()
+
+function(check_required_var VAR_NAME)
+  if(NOT ${VAR_NAME})
+    message(FATAL_ERROR "Variable ${VAR_NAME} is not set.")
+  endif()
+endfunction()
+
+set(_cpack_bsdsunix_fallback_origin "misc/bogus")
+
+_cpack_bsdsunix_fallback_var("CPACK_BSDSUNIX_PACKAGE_NAME"
+    "CPACK_PACKAGE_NAME"
+    "CMAKE_PROJECT_NAME"
+    )
+
+set(_cpack_bsdsunix_fallback_www "http://example.com/?pkg=${CPACK_BSDSUNIX_PACKAGE_NAME}")
+
+_cpack_bsdsunix_fallback_var("CPACK_BSDSUNIX_PACKAGE_COMMENT"
+    "CPACK_PACKAGE_DESCRIPTION_SUMMARY"
+    )
+
+# TODO: maybe read the PACKAGE_DESCRIPTION file for the longer
+#       BSDSUniX pkg-descr?
+_cpack_bsdsunix_fallback_var("CPACK_BSDSUNIX_PACKAGE_DESCRIPTION"
+    "CPACK_DEBIAN_PACKAGE_DESCRIPTION"
+    "CPACK_PACKAGE_DESCRIPTION_SUMMARY"
+    "PACKAGE_DESCRIPTION"
+    )
+
+# There's really only one homepage for a project, so
+# re-use the Debian setting if it's there.
+_cpack_bsdsunix_fallback_var("CPACK_BSDSUNIX_PACKAGE_WWW"
+    "CPACK_PACKAGE_HOMEPAGE_URL"
+    "CPACK_DEBIAN_PACKAGE_HOMEPAGE"
+    "_cpack_bsdsunix_fallback_www"
+    )
+
+_cpack_bsdsunix_fallback_var("CPACK_BSDSUNIX_PACKAGE_VERSION"
+    "CMAKE_PROJECT_VERSION"
+    "${CMAKE_PROJECT_NAME}_VERSION"
+    "PROJECT_VERSION"
+    "CPACK_PACKAGE_VERSION"
+    "CPACK_PACKAGE_VERSION"
+    )
+
+_cpack_bsdsunix_fallback_var("CPACK_BSDSUNIX_PACKAGE_MAINTAINER"
+    "CPACK_PACKAGE_CONTACT"
+    )
+
+_cpack_bsdsunix_fallback_var("CPACK_BSDSUNIX_PACKAGE_LICENSE"
+    "CPACK_RPM_PACKAGE_LICENSE"
+    )
+
+_cpack_bsdsunix_fallback_var("CPACK_BSDSUNIX_PACKAGE_ORIGIN"
+  "_cpack_bsdsunix_fallback_origin"
+  )
+
+if(NOT CPACK_BSDSUNIX_PACKAGE_CATEGORIES)
+  string(REGEX REPLACE "/.*" "" CPACK_BSDSUNIX_PACKAGE_CATEGORIES ${CPACK_BSDSUNIX_PACKAGE_ORIGIN})
+endif()
+
+check_required_var("CPACK_BSDSUNIX_PACKAGE_NAME")
+check_required_var("CPACK_BSDSUNIX_PACKAGE_ORIGIN")
+check_required_var("CPACK_BSDSUNIX_PACKAGE_VERSION")
+check_required_var("CPACK_BSDSUNIX_PACKAGE_MAINTAINER")
+check_required_var("CPACK_BSDSUNIX_PACKAGE_COMMENT")
+check_required_var("CPACK_BSDSUNIX_PACKAGE_DESCRIPTION")
+check_required_var("CPACK_BSDSUNIX_PACKAGE_WWW")
+check_required_var("CPACK_BSDSUNIX_PACKAGE_LICENSE")