+Set("INSTALL_DOC_DIR", '$(INSTALL_USR_PREFIX)share/doc');
+Set("INSTALL_PERL_DIR", '$(INSTALL_LIB_DIR)/perl5');
+
+# Remember PKG_CONFIG_PATH used for building, so that it will be propagated to
+# pkg-config's run locally in the makefiles.
+Set("PKG_CONFIG_PATH", $ENV{"PKG_CONFIG_PATH"}) if defined $ENV{"PKG_CONFIG_PATH"};