This shift I spent a while working on a ghc bug that is blocking the haskell transition. It turned out to really be a gold (linker) bug: https://sourceware.org/bugzilla/show_bug.cgi?id=26902 which fortunately has a simple fix which should land upstream and then in Debian and Ubuntu soon.
I then spent a while looking at python things. pandas should migrate when https://code.launchpad.net/~mwhudson/autopkgtest-cloud/+git/autopkgtest-cloud/+merge/393889 is merged and the dask tests retried and numpy is close to migrating with a bit of retrying. I think there is a genuine regression though in numpy on s390x causing python-meshio to fail tests. It is a tolerance based test and upstream has reacted to previous failure reports by just increasing the tolerance but I don't know if that's appropriate this time. Scipy is reported as triggering heaps of "regressions" but most of those are just because numpy hasn't migrated yet, I'm not sure it's worth retriggering them all with the corresponding triggers vs just getting numpy migrated.