Make a distinction between source and build directories.
test_description="emacs notmuch-hello view"
. $(dirname "$0")/test-lib.sh || exit 1
-EXPECTED=$TEST_DIRECTORY/emacs.expected-output
+EXPECTED=$NOTMUCH_SRCDIR/test/emacs.expected-output
add_email_corpus
test_description="emacs notmuch-show view"
. $(dirname "$0")/test-lib.sh || exit 1
-EXPECTED=$TEST_DIRECTORY/emacs-show.expected-output
+EXPECTED=$NOTMUCH_SRCDIR/test/emacs-show.expected-output
add_email_corpus
test_description="emacs tree view interface"
. $(dirname "$0")/test-lib.sh || exit 1
-EXPECTED=$TEST_DIRECTORY/tree.expected-output
+EXPECTED=$NOTMUCH_SRCDIR/test/tree.expected-output
add_email_corpus