diff -ur postgresql-18beta1/src/interfaces/Makefile pg18_patch/src/interfaces/Makefile
--- postgresql-18beta1/src/interfaces/Makefile	2025-05-05 20:25:46.000000000 +0000
+++ pg18_patch/src/interfaces/Makefile	2025-05-21 08:13:15.038986820 +0000
@@ -12,7 +12,7 @@
 top_builddir = ../..
 include $(top_builddir)/src/Makefile.global
 
-SUBDIRS = libpq ecpg
+SUBDIRS = libpq
 
 ifeq ($(with_libcurl), yes)
 SUBDIRS += libpq-oauth
Only in pg18_patch/src/interfaces: Makefile.orig