How to correctly copy a file when building an image on Docker Hub?

I have a fairly simple Dockerfile, which works locally. However, when I build it on Docker Hub I get the following error:

Starting build of index.docker.io/adius/tasklite:next...Step 1/16 : from haskell:8.8.4 as builder---> 3ae1aa658125Step 2/16 : workdir tasklite---> Running in 73fa9ffd738eRemoving intermediate container 73fa9ffd738e---> cdacdf2fede2Step 3/16 : copy docker-stack.yaml stack.yamlCOPY failed: stat /var/lib/docker/tmp/docker-builder266377042/docker-stack.yaml: no such file or directory

The build configuration seems to be fine as well:

How can I fix this?