AC_ARG_ENABLE(userdb-cache, AS_HELP_STRING([--enable-userdb-cache],[build with userdb-cache support]),enable_userdb_cache=$enableval,enable_userdb_cache=yes)
AC_ARG_ENABLE(launchd, AS_HELP_STRING([--enable-launchd],[build with launchd auto-launch support]),enable_launchd=$enableval,enable_launchd=auto)
-AC_ARG_WITH(xml, AS_HELP_STRING([--with-xml=[libxml/expat]],[XML library to use]))
+AC_ARG_WITH(xml, AS_HELP_STRING([--with-xml=[libxml/expat]],[XML library to use (libxml may be named libxml2 on some systems)]))
AC_ARG_WITH(init-scripts, AS_HELP_STRING([--with-init-scripts=[redhat]],[Style of init scripts to install]))
AC_ARG_WITH(session-socket-dir, AS_HELP_STRING([--with-session-socket-dir=[dirname]],[Where to put sockets for the per-login-session message bus]))
AC_ARG_WITH(test-socket-dir, AS_HELP_STRING([--with-test-socket-dir=[dirname]],[Where to put sockets for make check]))