Update and tidy the build system for autothing v3.

1 files changed, 8 insertions, 7 deletions

diff --git a/config.mk b/config.mk
index 69a1bb9..0d564e0 100644
--- a/config.mk
+++ b/config.mk
@@ -2,16 +2,15 @@
 #       indicate what the GNU standards dictate, when our values
 #       differ.  We're not a GNU package.
 
-ifeq ($(topsrcdir),)
+ifeq ($(origin topsrcdir),undefined)
+topsrcdir := $(patsubst %/,%,$(dir $(lastword $(MAKEFILE_LIST))))
+topoutdir := $(topsrcdir)
 
-topoutdir := $(patsubst %/,%,$(dir $(lastword $(MAKEFILE_LIST))))
-topsrcdir := $(topoutdir)
-
-MAKEFLAGS += --warn-undefined-variables
-include $(topsrcdir)/build-aux/no-builtin-variables.mk
+# In case .srcversion-libretools.mk hasn't been generated yet.
+LIBRETOOLS_VERSION ?= 0
 
 PACKAGE = libretools
-VERSION = $(firstword $(LIBRETOOLS_VERSION) 0)
+VERSION = $(LIBRETOOLS_VERSION)
 
 DESTDIR =
 
@@ -35,4 +34,6 @@ RONNFLAGS = --manual='libretools Manual' --organization='Parabola'
 
 TESTENVFLAGS ?=
 
+.LIBPATTERNS ?=
+
 endif