assumes the simpler I/O model.
Exim must *not* be built with HEADERS_CHARSET set to UTF-8.
+(11) If building any dynamically-loaded lookups, LOOKUP_MODULE_DIR should
+ be set to .../exim/test/eximdir.
+
OPTIONAL EXTRAS
the current environment. The former are kept in the directory aux-fixed. The
latter are distributed in the directory aux-var-src, and copied with the
standard substitutions into the directory aux-var at the start of each test
-run.
+run (with TESTNUM from the numeric prefix of the filename is there is one).
Most of the auxiliary files have names that start with a test number,
indicating that they are specific to that one test. A few fixed files (for