[PATCH 01/10] maint: make it easier to update expectations

* tests/local.mk (update-tests): New.
---
 README-hacking.md | 2 +-
 tests/local.mk    | 8 ++++++++
 2 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/README-hacking.md b/README-hacking.md
index e128efb3..b5245bb9 100644
--- a/README-hacking.md
+++ b/README-hacking.md
@@ -444,7 +444,7 @@ added the `[-Wother]` part to all the warnings).  Part of the update can be
 done with a crude tool: `build-aux/update-test`.
 
 Once you ran the test suite, and therefore have many `testsuite.log` files,
-run, from the source tree:
+run `make update-tests`.  Or, by hand, from the *source* tree:
 
     $ ./build-aux/update-test $build/tests/testsuite.dir/*/testsuite.log
 
diff --git a/tests/local.mk b/tests/local.mk
index 469b1896..2599c059 100644
--- a/tests/local.mk
+++ b/tests/local.mk
@@ -36,6 +36,14 @@ $(top_srcdir)/%D%/package.m4: $(top_srcdir)/configure
 	} >[email protected]
 	$(AM_V_at)mv [email protected] $@
 
+
+# Update the test cases.  Consider the latest test result to be the
+# correct expectations, and change the test cases to match them.
+.PHONY: update-tests
+update-tests:
+	$(AM_V_GEN)cd $(top_srcdir) \
+	  && build-aux/update-test $(abs_builddir)/%D%/testsuite.dir/*/testsuite.log
+
 ## ------------------------- ##
 ## Generate the test suite.  ##
 ## ------------------------- ##
-- 
2.27.0