Just in case anyone else runs into this and doesn't know what's going on: we had a problem with Yarn 1.0, because it doesn't recognise repositories that don't end in a trailing slash -- for example, "@folio:registry=https://repository.folio.org/repository/npm-folio" is no good any more, but "@folio:registry=https://repository.folio.org/repository/npm-folio/" is. See https://github.com/folio-org/stripes-demo-platform/commit/f8...

Meanwhile ... I do regret that this doesn't introduce alternative dependencies, like Debian packages have, where your package foo can have dependency on "either bar or baz". Oh well.