Dear schroot maintainer, When using type=directory and union-type=overlay, sometimes appending custom mount options is essential. Currently, setting `union-mount-options` could override all existing options like lowerdir, upperdir, workdir. Support appending `union-mount-options` could be useful for options like `xino=off`. Sincerely, Tianyu Chen @ Deepin
Being a feature request this needs to be adressed upstream. Cheers, sur5r