Add configure as a prerequisite for Autotest package.m4.

The information put in package.m4, for example the package version,
comes from the configure script.  When these are updated in the
source tree we want to update this too so that the testsuite gets
updated information.

diff --git a/snippet/autotest.mk b/snippet/autotest.mk
index 0a10c9f792b688b4b4b666153908d81fce4c7f09..d5adc9d23f49c938f421103f888d8eadeaad1c80 100644 (file)
--- a/snippet/autotest.mk
+++ b/snippet/autotest.mk
@@ -1,4 +1,4 @@
-# Copyright © 2015,2019 Nick Bowler
+# Copyright © 2015,2019-2020 Nick Bowler
 #
 # Automake fragment to hook up a basic Autotest test suite into the build.
 # It is expected that a testsuite.at file exists in $(srcdir).  The
@@ -34,7 +34,7 @@ maintainer-clean-autotest:
        rm -f testsuite package.m4
 .PHONY: maintainerclean-autotest
 
-package.m4:
+package.m4: $(top_srcdir)/configure.ac
        $(AM_V_GEN) :; { \
          printf 'm4_define([%s], [%s])\n' \
            AT_PACKAGE_NAME      '$(PACKAGE_NAME)' \