The last question,I think :

root@devuan:~/Desktop/qemu-v5.1.0# apt install libusb-dev

root@devuan:~/Desktop/qemu-v5.1.0# ./configure --target-list=arm-softmmu
--enable-opengl --enable-gtk --enable-kvm --enable-guest-agent
--enable-spice --audio-drv-list="oss pa" --enable-libusb

ERROR: User requested feature libusb
       configure was not able to find it.
       Install libusb devel >= 1.0.13

root@devuan:~/Desktop/qemu-v5.1.0# apt search libusb-dev

Sorting... Done
Full Text Search... Done
libusb-dev/stable,now 2:0.1.12-32 armhf [installed]
userspace USB programming library development files

What's the reason for this error ? I've installed libusb-dev 2.0 that's
greater than 1.0.13,but it is not recognized.

--
Mario.