(CI) don't read from docker on start-up, could contain header

Author: MatthijsBurgh

.ci/install.bash

@@ -69,7 +69,11 @@ then
     DOCKER_MOUNT_KNOWN_HOSTS_ARGS="--mount type=bind,source=${HOME}/.ssh/known_hosts,target=/tmp/known_hosts_extra"
 fi
 
-DOCKER_HOME=$(docker run --name tue-env --rm "${IMAGE_NAME}:${BRANCH_TAG}" bash -c 'echo "${HOME}"' | tr -d '\r')
+# Docker container can show a header on start-up. We don't want to capture it
+docker run --detach --tty --name tue-env "${IMAGE_NAME}:${BRANCH_TAG}"
+DOCKER_HOME=$(docker exec -t tue-env bash -c 'echo "${HOME}"' | tr -d '\r')
+docker stop tue-env  &> /dev/null || true
+docker rm tue-env &> /dev/null || true
 
 # Make sure the ~/.ccache folder exists
 mkdir -p "$HOME"/.ccache