xt/ is typically reserved for "eXtended tests" intended for
the maintainers and not ordinary users. Since these require
special configuration and do nothing by waste cycles
during startup, they qualify.
t/filter_subjecttag.t
t/filter_vger.t
t/git-http-backend.psgi
-t/git-http-backend.t
t/git.fast-import-data
t/git.t
t/hl_mod.t
t/msgtime.t
t/nntp.t
t/nntpd-tls.t
-t/nntpd-validate.t
t/nntpd.t
t/nulsubject.t
t/over.t
-t/perf-msgview.t
-t/perf-nntpd.t
-t/perf-threading.t
t/plack.t
t/precheck.t
t/psgi_attach.t
t/watch_maildir_v2.t
t/www_listing.t
t/xcpdb-reshard.t
+xt/git-http-backend.t
+xt/nntpd-validate.t
+xt/perf-msgview.t
+xt/perf-nntpd.t
+xt/perf-threading.t