Hello Bastian, Many thanks for the link, it does indeed look like the exact same bug!
So, this turns out to be a longstanding bug in libfile-rsyncp-perl. I see two ways to fix this problem in Debian: - update libfile-rsyncp-perl to 0.76 in buster. This seems quite unlikely but I'm not 100% familiar with Debian policies. - wait for upstream rsync to (possibly) revert the default behaviour of rsync, that is, disable --msgs2stderr by default. And then wait for this updated version of rsync to land in bullseye. See https://github.com/WayneD/rsync/issues/95#issuecomment-700424731 It also looks quite unlikely. So I guess we need the workarounds for now :/ Baptiste
