Pushing to Github doesn't work from Github action

[nightscape]

I'm trying to setup a CI workflow using Github actions.
When sbt-ci-release-early tries to push the created tag back to Github, the following error occurs:

[info] pushing v0.12.5 to https:/crealytics/spark-excel
[info] env var GITHUB_TOKEN found, trying to interweave it with the remote uri (https:/crealytics/spark-excel)
fatal: could not read Password for 'https://***@github.com': No such device or address
[error] java.lang.AssertionError: assertion failed: failed to push the new tag to the remote (https://***@github.com/crealytics/spark-excel)
[error] Use 'last' for the full log.
##[error]Process completed with exit code 1.

The interweaveGithubToken method inserts only the GITHUB_TOKEN into the URL, whereas git seems to expect both a user name and a password.

One Github action for pushing to Github inserts GITHUB_ACTOR as user and the GITHUB_TOKEN as password.

Would this be an option here to?