diff --git a/src/test/perl/README b/src/test/perl/README
index 0e9a00ea05..f75b224175 100644
--- a/src/test/perl/README
+++ b/src/test/perl/README
@@ -12,22 +12,29 @@ $(prove_installcheck) targets in Makefile.global. By default every test in the
 t/ subdirectory is run. Individual test(s) can be run instead by passing
 something like PROVE_TESTS="t/001_testname.pl t/002_othertestname.pl" to make.
 
-You should prefer to write tests using pg_regress in src/test/regress, or
-isolation tester specs in src/test/isolation, if possible. If not, check to
-see if your new tests make sense under an existing tree in src/test, like
-src/test/ssl, or should be added to one of the suites for an existing utility.
-
-Note that all tests and test tools should have perltidy run on them before
-patches are submitted, using perltidy --profile=src/tools/pgindent/perltidyrc
-
 By default, to keep the noise low during runs, we do not set any flags via
 PROVE_FLAGS, but this can be done on the 'make' command line if desired, eg:
 
 make check-world PROVE_FLAGS='--verbose'
 
+When a test fails, the terminal output from 'prove' is usually not sufficient
+to diagnose the problem.  Look into the log files that are left under
+tmp_check/log/ to get more info.  Files named 'regress_XXX' are log output
+from the perl test scripts themselves, and should be examined first.
+Other files are postmaster logs, and may be helpful as additional data.
+
+
 Writing tests
 -------------
 
+You should prefer to write tests using pg_regress in src/test/regress, or
+isolation tester specs in src/test/isolation, if possible. If not, check to
+see if your new tests make sense under an existing tree in src/test, like
+src/test/ssl, or should be added to one of the suites for an existing utility.
+
+Note that all tests and test tools should have perltidy run on them before
+patches are submitted, using perltidy --profile=src/tools/pgindent/perltidyrc
+
 Tests are written using Perl's Test::More with some PostgreSQL-specific
 infrastructure from src/test/perl providing node management, support for
 invoking 'psql' to run queries and get results, etc. You should read the