Cannot link against static libzip with additional dependencies by default

[endrift]

Describe the Bug When using find_package to import libzip and linking against a static libzip::zip built against bzip2 and/or liblzma, it cannot be used without first manually importing BZip2::BZip2 or LibLZMA::LibLZMA.

Expected Behavior The libzip::zip target should be able to be linked against without having to do any manual searching for packages on consumer's end. It would be extremely fragile to require that on a case-by-case basis since future versions may have different dependencies.

Observed Behavior The targets that attempt to link against libzip::zip throw errors that the targets BZip2::BZip2 and/or LibLZMA::LibLZMA cannot be found.

To Reproduce

• First staticly build and install libzip with bzip2 or xz support
• Make a blank file called test.c, and make a CMakeLists.txt file in the same directory containing this:

find_package(libzip REQUIRED)
add_executable(test test.c)
target_link_libraries(test libzip::zip)

• Run cmake . and cmake --build .. Observe warnings and errors.

libzip Version 1.7.3

Operating System This was done with the msys2-provided build of 1.7.3 but should apply universally.

Test Files N/A

Additional context I asked in #cmake on FreeNode to see if it was a CMake issue or a libzip issue, where it was suggested that you should handle the necessary find_package calls in your exported config (so presumably libzip-config.cmake.in). However, they would consider adding a feature for at least partial detection and export of target dependencies.

[0-wiz-0]

Thanks. I agree that this should be fixed. It seems you investigated this already, can you please come up with a patch?

[endrift]

I investigated what went wrong. I can try and investigate a fix, but that was a bit beyond the scope of what I was investigating. I'll look into it tomorrow. Still getting the hang of CMake in this repo?

[0-wiz-0]

Yeah, and some of the details of how to do this "right" are fiddly and underdocumented... Thanks!

[endrift]

I looked into this but I wasn't sure how to fix it properly, so I've been doing other things instead in the meantime.

[0-wiz-0]

Did you make progress? Or do you have pointers to more details what fixes would be needed?

[endrift]

Unfortunately I got stuck when I realized that the Find*.cmake files that libzip uses internally don't get exported, so I'm not really sure how to fix this properly either. I ended up moving on to other projects in the meantime.