Red-faced question: There is a Perl package, libdevice-usb-perl, in which C code is "inlined" (using Perl package libinline-c-perl). The first statement of the inlined C code is #include <usb.h> The query https://packages.debian.org/search?searchon=contents&keywords=usb.h shows many results, even for the AMD arch needed. Is one of these the included file? Or is it somewhere else? Thank you.