Demi Marie Obenour <demiobenour@gmail.com> writes:

> The following command fails to rebuild the image:
>
> $ nix-shell --run 'make clean && make run-qemu'
>
> The following command succeeds:
>
> $ nix-shell --pure --run 'make clean' && nix-shell --pure --run 'make run-qemu'
>
> Interactive Nix shells exhibit the same problems, and adding
> --pure to the first invocation does not help.

Works for me on 560fd87 in img/app.  What were you testing?  Logs?