See https://postgr.es/m/eb249761-56e2-4e42-a2c5-b9ae18c1ca1f%40technowledgy.de
---
--- a/src/makefiles/Makefile.darwin
+++ b/src/makefiles/Makefile.darwin
@@ -5,6 +5,8 @@ DLSUFFIX = .so
 # env var name to use in place of LD_LIBRARY_PATH
 ld_library_path_var = DYLD_LIBRARY_PATH
 
+export_dynamic = -Wl,-export_dynamic
+
 ifdef PGXS
   BE_DLLLIBS = -bundle_loader $(bindir)/postgres
 else