The rust-ringbuf package was recently updated from 0.3 to 0.5, breaking
the (build-)dependencies of rust-futures-ringbuf

Unfortunately the ringbuf crate does not seem to provide a changelog
and a quick attempt at a dependency bump produced a bunch of errors.

There does not seem to have been any upstream activity on the
futures-ringbuf crate for over three years

There do not appear to be any packages that depend on
rust-futures-ringbuf as a build- or runtime dependency, there does
seem to be one package that depends on it as a test dependency,
that package being rust-multistream-select

rust-multistream-select in-turn does not seem to have any reverse
dependencies at all (not even test dependencies).

Dear submitter,

as the package rust-futures-ringbuf has just been removed from the Debian archive
unstable we hereby close the associated bug reports.  We are sorry
that we couldn't deal with your issue properly.

For details on the removal, please see https://bugs.debian.org/1150644

The version of this package that was in Debian prior to this removal
can still be found using https://snapshot.debian.org/.

Please note that the changes have been done on the master archive and
will not propagate to any mirrors until the next dinstall run at the
earliest.

This message was generated automatically; if you believe that there is
a problem with it please contact the archive administrators by mailing
ftpmaster@ftp-master.debian.org.

Debian distribution maintenance software
pp.
Thorsten Alteholz (the ftpmaster behind the curtain)