I think nativesdk-icecc is broken for multilib SDKs. icecc-env.sh uses TUNE_PKGARCH to name the configuration, but in a multilib SDK there are multiple configurations available. The environment and setup scripts should probably just use TARGET_PREFIX which is exported by the environment scripts (e.g. mips64-poky-linux-gnun32-) as part of the naming, and handle the setup script being called for each environment.
Patches on the list
Fixed in oe-core:13704d7a9d147382169d0c4bd77cb4f5577c65b1