env REMOTE_TEMPORARY_FILE_DIRECTORY=/ssh:host:/tmp make ...
+\f
+There are also continuous integration tests on
+<https://hydra.nixos.org/jobset/gnu/emacs-trunk> (see
+admin/notes/hydra) and <https://emba.gnu.org/emacs/emacs>. Both
+environments provide an environment variable, which could be used to
+determine, whether the tests run in one of these test environments.
+
+$EMACS_HYDRA_CI indicates the hydra environment, and $EMACS_EMBA_CI
+indicates the emba environment, respectively.
+
\f
(Also, see etc/compilation.txt for compilation mode font lock tests.)