Guix QEMU built without libusb support

[白い熊＠相撲道]

I'd like to use QEMU in GuixSD with direct USB passthrough support. 
However, "info usbhost" in QEMU monitor gives me "usb host devices not 
supported". I think this means the recipe for QEMU in Guix builds QEMU 
without libusb and thus it doesn't support host devices.

Looking at qemu description in guix doesn't list libusb as a dependency, 
so that strengthens my suspicion.

I haven't experimented with Guix package recipes yet and so am not 
advanced enough to modify the Scheme file and build it locally yet, so 
I'd like to request help here - if this is indeed the case - if someone 
could modify the recipe and push to the repository, so QEMU would be 
built with libusb support to enable the USB host functionality.

Could anyone do this? Many thanks.
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白い熊＠相撲道