pkg-config file does not list libusb as a requirement

[classabbyamp]

many pkgconfig files for programs that link against libusb have a Requires.private: libusb-1.0 >= x.x.x in the .pc file. Can this be added to libairspyhf's pkgconfig file?

[touil]

What actual problem are you trying to solve by restricting libusb versions?

[classabbyamp]

if there's no version restriction on libusb for airspyhf, then that's fine, I was just giving an example. However, the pkgconfig file does not mention the libusb build dependency, which means that someone using the pkgconfig file for a project depending on libairspyhf would not explicitly know what the dependencies are. libairspy has this same issue.

Requires: A list of packages required by this package. The versions of these packages may be specified using the comparison operators =, <, >, <= or >=.
Requires.private: A list of private packages required by this package but not exposed to applications. The version specific rules from the Requires field also apply here.

(https://people.freedesktop.org/~dbn/pkg-config-guide.html#concepts)

[ahopper]

There does appear to be a minimum libusb version of 1.0.23 caused by the use of libusb_wrap_sys_device.
I think the use of libusb_interrupt_event_handler also requires 1.0.21