Transferring a file using rsync on a system where /proc is not mounted results in the following error: rsync: [receiver] failed to set permissions on "/some_file": Operation not supported (95) This issue was already acknowledged and discussed upstream: [https://serverfault.com/questions/1059618/rsync-generator-failed-to-set-permissions-operation-not-supported-95] [https://github.com/WayneD/rsync/issues/109] [https://sourceware.org/bugzilla/show_bug.cgi?id=26401]
