Most failures appear in the ICON fixes and are caused by changes in how Iris handles meshes in the upcoming 3.10 release: https://github.com/SciTools/iris/releases/tag/v3.10.0rc0. Maybe @schlunma could have a look at these?

I will do that once Iris 3.10 is out. Some of the fails are also related to iris-esmf-regrid, so we also have to wait until they fixed their mesh handling.

thank you lots, gents! We still need a structured approach to flagging/dealing with these types of fails. Let's chat about it in person (2d-person) on our next week's TLT (we may have to postpone it if peeps are on holidays)

Update: iris-esmf-regrid just published a new release where they address iris' new API in a nice backwards-compatible way: https://github.com/SciTools-incubator/iris-esmf-regrid/releases/tag/v0.11.0. We should do the same 👍

I implemented a draft PR that uses the latest iris release candidate here: #2500. Everything seems to work fine, also the test_with_upstream_developments run successfully now 👍

EDIT: I did not implement it in a backwards-compatible way but rather pinned iris so we can use its new features (and get rid of 300+ lines!)

I like that, and also commented there that'd I'd be very happy to review it, many thanks, Manu! About being strictly incompatible with older than latest irises, I am in two boats about it - what if the shiniest latest iris proves out to have a major bug, and we need to wait until they fix it and release a patched, new version - we using the buggy iris since we can't revert to an older one - may take would be to have support for at least one lesser iris version - @bouweandela (hope you back from :beach: ) what you think?

I agree that it would be nice to support multiple versions of iris, but that may be a luxury we cannot afford at the moment. Let's talk about it at the next tech lead team meeting.

good call, bud!
Another point about this test (before I forget it): we should prob not run it in PRs - people get very confused why their stuff is failing, run it on main only