Lantiq: bad sdk or PEBKAC?

Hello, I'm trying to build my package using the 21.02.1 sdk for the lantiq xway using github actions, but it chokes on the ltq-tapi package.
Previously I successfully used (locally) the sdk for version 19.07.2 so I don't know if I'm doing something wrong or the sdk is broken.
I tried a github action to compile ltq-tapi for 19.07.8 and it succeeds.
This is what I do to test

          ./scripts/feeds update -a
          ./scripts/feeds install -a
          make defconfig
          make -j1 V=s package/ltq-tapi/compile

Here's a successful run for 19.07.8 and here's the failing one for 21.02.1