Without this we get the wrong libdir

prefix=/usr
exec_prefix=${prefix}/bin
libdir=${prefix}//usr/lib64
includedir=${prefix}/include

--- libcares.pc.cmake
+++ libcares.pc.cmake
@@ -7,9 +7,9 @@
 # Copyright (C) The c-ares project and its contributors
 # SPDX-License-Identifier: MIT
 prefix=@CMAKE_INSTALL_PREFIX@
-exec_prefix=${prefix}/@CMAKE_INSTALL_BINDIR@
-libdir=${prefix}/@CMAKE_INSTALL_LIBDIR@
-includedir=${prefix}/@CMAKE_INSTALL_INCLUDEDIR@
+exec_prefix=@CMAKE_INSTALL_FULL_BINDIR@
+libdir=@CMAKE_INSTALL_FULL_LIBDIR@
+includedir=@CMAKE_INSTALL_FULL_INCLUDEDIR@
 
 Name: c-ares
 URL: https://c-ares.org/