[libusb] Fixing the error of not being able to locate Libusb header files.

[Zheng-Bicheng]

No description provided.

[Zheng-Bicheng]

I assume I have located and resolved this issue.

• CMake Cannot Find Libusb Header Files #35558

[Zheng-Bicheng]

@JonLiu1993

[dg0yt]

No. The wrapper isn't a wrapper, and it is about to be removed: #35498
Use pkg_check_modules.
Or add an unofficial-libusb-config.cmake.

[Zheng-Bicheng]

No. The wrapper isn't a wrapper, and it is about to be removed: #35498 Use pkg_check_modules. Or add an unofficial-libusb-config.cmake.

I'm sorry, I didn't understand what 'The wrapper isn't a wrapper' means; it runs fine after I made local modifications.If someone else has already submitted a PR to fix this issue, I can wait for the PR to be completed.

[dg0yt]

find_package(libusb) somewhat works because vcpkg loads vcpkg-make-wrapper.cmake.
But there is no official find modules or config for libusb which would define an official cmake interface. Wrapper are meant to complement the official interface, e.g. add transitive usage requirements. They shall not completely take over the role of find modules or config.

libusb provides usage information via pkg-config. This is the official, portable interface, and it can be used in CMake, although with some limitations.

If there is still a desire to provide (and maintain) a CMake package, the wrapper must be ported to an unofficial cmake config, with a distinct name and target namespace, to signal the lock-in effect.
https://learn.microsoft.com/en-us/vcpkg/contributing/maintainer-guide#add-cmake-exports-in-an-unofficial--namespace

[JonLiu1993]

Duplicate of #35498.