follow link2xt advise and don't check subject/body at all -- turns out there were no tests anyway.

scripts/deploy.sh

@@ -1,15 +1,10 @@
 #!/usr/bin/env bash
+: ${CHATMAIL_DOMAIN:=c1.testrun.org}
+export CHATMAIL_DOMAIN
 
-echo -----------------------------------------
+chatmaild/venv/bin/python3 -m build -n --sdist chatmaild --outdir dist
-echo deploying to $CHATMAIL_DOMAIN 
-echo -----------------------------------------
 
-echo WARNING: in five seconds deploy to $CHATMAIL_DOMAIN starts
+deploy-chatmail/venv/bin/pyinfra --ssh-user root "$CHATMAIL_DOMAIN" \
-sleep 5
-
-venv/bin/python3 -m build -n --sdist chatmaild --outdir dist
-
-venv/bin/pyinfra --ssh-user root "$CHATMAIL_DOMAIN" \
     deploy-chatmail/src/deploy_chatmail/deploy.py
 
 rm -r dist/