tardiff /usr/portage/distfiles/postgresql-10.15.tar.bz2 -upN
--- postgresql-10.15/src/include/utils/pg_locale.h
+++ postgresql-10.15/src/include/utils/pg_locale.h	2021-02-09 12:03:19.403549986 -0800
@@ -17,6 +17,7 @@
 #endif
 #ifdef USE_ICU
 #include <unicode/ucol.h>
+#undef bool
 #endif
 
 #include "utils/guc.h"