--- postgresql-15.2/configure.ac	2023-03-07 23:33:54.935049910 +0100
+++ postgresql-15.2/configure.ac	2023-03-07 23:34:17.590329155 +0100
@@ -1106,7 +1106,7 @@
 # Assignments
 #
 
-CPPFLAGS="$CPPFLAGS $INCLUDES"
+CPPFLAGS="$CPPFLAGS -DALLOW_ABSOLUTE_DBPATHS $INCLUDES"
 LDFLAGS="$LDFLAGS $LIBDIRS"
 
 AC_ARG_VAR(LDFLAGS_EX, [extra linker flags for linking executables only])