argunix: pushing drv closure to `us` failed:
`nix copy` exited Some(1) (direction="to"): don't know how to build these paths:
  /nix/store/q74f5c7nsx246xwrwvm359gd3km48qcf-qemu-iso.drv
error: path '/nix/store/q74f5c7nsx246xwrwvm359gd3km48qcf-qemu-iso.drv' is required, but there is no substituter that can build it

argunix: drv=/nix/store/q74f5c7nsx246xwrwvm359gd3km48qcf-qemu-iso.drv