I am leaving some notes here, in case someone else experiences a similar situation and is being sent here by a search engine. To find out what was going on in a similar case, I ran
docker-compose run --rm app /bin/bash
and typed the rsync command from
or similar manually, by invoking
rsync -rlD --delete --exclude-from=/upgrade.exclude /usr/src/nextcloud/ /var/www/html/
on the shell and at least reproducing the same error.
Trying to find out which resource was using it
apt update && apt install -y lsof didn’t yield the expected result. The file was also not accessed anywhere in the host system. What happened?
It turned out there was still a host volume mounted in that directory, so it could not be removed. Taking it out in the
docker-compose.yml file helped resolving the update blocker.
May it be that you mounted the
logs directory via a Docker volume, too?