add_email_corpus threading
test_begin_subtest "reply to ghost"
-notmuch show --entire-thread=true id:000-real-root@example.org | grep ^Subject: | head -1 > OUTPUT
+notmuch show --entire-thread=true id:000-real-root@example.org | grep ^Subject: | head -1 > OUTPUT
cat <<EOF > EXPECTED
Subject: root message
EOF