I just stumbled across this error:
Error response from daemon: create drone-xaux5fkwjzlpgmshffdm: volume name “drone-xaux5fkwjzlpgmshffdm” cannot be a reserved word for Windows filenames
AFAICT it is related to the fact that AUX is in the filename. See this stackoverflow question which shows a similar problem:
This looks to me like a bug - but is it a docker bug or a drone bug? I would expect one or the other to sanitize the name, but as the name is in part inspired by drone, perhaps it should be done by drone, prior to sending the name to docker.