As Simon pointed out in comment #4, his workaround will only work if the private store hasn't enabled authentication. I think long term, 'snap download' needs to be re-worked to use snapd directly for downloads, which would allow proper store authentication to occur.
@Michael
As Simon pointed out in comment #4, his workaround will only work if the private store hasn't enabled authentication. I think long term, 'snap download' needs to be re-worked to use snapd directly for downloads, which would allow proper store authentication to occur.