Reopening after accidentally having deleted the branch.

Huh, saying that this is not where I'd have expected the error to show up would be putting it mildly -- I'm having a look at why this fails, but it may take a while.

I have no clue what caused the build failure, and can not reproduce the issue locally (after building the container in podman and using BOARDS="arduino-uno esp32-wroom-32 hifive1b msb-430h native samr21-xpro" make -C examples/rust-gcoap BUILD_IN_DOCKER=1 DOCKER=podman DOCKER_IMAGE=localhost/riotbuild:latest buildtest to run the very test that CI should have run).

Let's see if it was a random glitch (like, file system error?), restarting the build test.

Seems that builds break due to files left over from other runs. Switching to draft PR to prevent accidental merging just because a test happens to fix it.

I suspect now that this is due to changes in some base image, and would break in master just as well.

I still can't make progress for lack of a way to reproduce it (works locally), so I'm triggering a master rebuild to cut down the space.