This .so is for an optional alternate optimiser (bumps is an interface
to various different optimisers for numerical fitting problems).
The optional optimiser is compiled and included in an arch:any package
(bumps-private-libs) while bumps itself is pure Python and arch:all.
bumps-private-libs is in the Recommends of python3-bumps; unfortunately,
bumps-private-libs is not available on all architectures. It could be an
arch-dependent Depends but it's an optional component (and an
arch-specific Depends means keeping an arch list in sync in two
different places).
The symlink could move into the bumps-private-libs package, but that is
only a cosmetic fix - the failure for `CDLL` in
`bumps/dream/compiled.py` would be basically the same, and we'd replace
this bug with a "missing depends on $arch" bug instead.
I'm not sure what the nicest solution is -- the current arrangement is
what we thought was the best option at the time.