(gnu_rel_host): Define.

(url_dir_list): Choose from (alpha|ftp).gnu.org depending
on whether $(VERSION) looks like a major release number.

Makefile.cfg

@@ -1,8 +1,14 @@
 # -*- makefile -*-
 ## Customize Makefile.maint.
 
+# If the version number matches /^\d+.\d+.\d$/ or /[a-z]$/, use alpha.gnu.org.
+# Otherwise, use ftp.gnu.org.
+gnu_rel_host := \
+  $(shell perl -e \
+    'print "$(VERSION)" =~ /^(\d\.\d\.\d|.*[a-z])$$/ ? "alpha" : "ftp"')
+
 url_dir_list = \
-  ftp://alpha.gnu.org/gnu/fetish \
+  ftp://$(gnu_rel_host).gnu.org/gnu/fetish \
   http://fetish.sf.net \
 
 # Files to update automatically.