Cannot build for ppc64le

Unable to build Veloren for powerpc systems. It requires an x86 extension, although I might be reading this wrong. This is with rust nightly on Debian stable:

error[E0635]: unknown feature mmx_target_feature --> /home/user/.cargo/registry/src/github.com-1ecc6299db9ec823/packed_simd-0.3.3/src/lib.rs:213:5 | 213 | mmx_target_feature, | ^^^^^^^^^^^^^^^^^^

Compiling directories-next v1.0.1 error: aborting due to previous error

For more information about this error, try rustc --explain E0635. error: could not compile packed_simd

To learn more, run the command again with --verbose. warning: build failed, waiting for other jobs to finish... error: build failed