Cross compile in bud

[jwygoda]

I'm having trouble making bud build a sd card for my raspberry pi.

I'm getting the following error when executing bud build rpi3 sd-aarch64:
error: Package ‘uboot-rpi_3_defconfig-2021.04’ in /nix/store/bwi8ibq0f0phc01cd6mqsz5hfm27zwgr-source/pkgs/misc/uboot/default.nix:101 is not supported on ‘x86_64-linux’, refusing to evaluate

How can I get an aarch64-linux build?

I've set boot.binfmt.emulatedSystems = [ "aarch64-linux" ]; on host that is tryng to execute bud build command.

[jwygoda]

I had to set system in flake.nix to aarch64-linux.