Port to GNU make 4.4

* cfg.mk (PATH): Assign eagerly, and simplify shell use, avoiding
use of the shell entirely if PWD is set, as it should be.
Problem reported by Sergei Trofimovich in:
https://lists.gnu.org/r/autoconf-patches/2022-09/msg00007.html

diff --git a/cfg.mk b/cfg.mk
index 7e515130662caf435c6cd08c69d7a74ec6824af7..82e896eddcee8ff69b8be4fc4d41617e78fefecf 100644 (file)
--- a/cfg.mk
+++ b/cfg.mk
@@ -18,7 +18,7 @@
 # This file is '-include'd into GNUmakefile.
 
 # Build with our own versions of these tools, when possible.
-export PATH = $(shell echo "`pwd`/tests:$$PATH")
+export PATH := $(or $(PWD),$(shell pwd))/tests:$(PATH)
 
 # Remove the autoreconf-provided INSTALL, so that we regenerate it.
 _autoreconf = autoreconf -i -v && rm -f INSTALL