Trying to create package, can't find header file

[Kaaserne]

My main library, looks like this:

add_requires("fmt >=5")

target("cpp-lazy")
    set_kind("headeronly")
    add_includedirs("include", { public = true })
    add_packages("fmt", { public = true })
target_end()

I'm trying to create a package file, so I can upload it to xmake-repo, the repo file looks as follows:

package("cpp-lazy")
    -- boilerplate ...
    add_versions("7.0.2", "4b10c705f8dd04e174e6eae588700d18e7ea91b897bc2515edfca4221dfed87e")
    on_install("windows", "macosx", "linux", function (package)
        import("package.tools.xmake").install(package)
    end)

    on_test(function(package)
        assert(package:check_cxxsnippets({test = [[
        void test() {
            int arr[]{1, 2, 3, 4};
            auto mapper{lz::map(arr, [](const int i) { return i + 1; })};
        }
    ]]}, {includes = "Lz/Map.hpp"})) -- probably fails here
    end)

Then, in another project, to test everything went well, I import cpp-lazy as follows:

add_requires("cpp-lazy")

target("main")
    set_kind("binary")
    add_files("main.cpp")
    add_packages("cpp-lazy", { public = true })

But, when compiling, I get:

0A8572B12ED84E3FB1FDE34F70EE1E33.cpp
C:\Users\marcd\AppData\Local\Temp\.xmake\230210\_0A8572B12ED84E3FB1FDE34F70EE1E33.cpp(2): fatal error C1083: Cannot open include file: 'Lz/Map.hpp': No such file or directory
  ${yellow}> in ${bright}C:\Users\marcd\AppData\Local\Temp\.xmake\230210\_0A8572B12ED84E3FB1FDE34F70EE1E33.cpp
if you want to get more verbose errors, please see:
  -> C:\Users\marcd\AppData\Local\.xmake\cache\packages\2302\c\cpp-lazy\7.0.2\installdir.failed\logs\install.txt
error: install failed!

[waruqi]

target("cpp-lazy")
set_kind("headeronly")
add_includedirs("include", { public = true })
add_packages("fmt", { public = true })
target_end()

you need use add_headerfiles("") to install header files. Lz/Map.hpp ...

https://xmake.io/#/manual/project_target?id=targetadd_headerfiles

[Kaaserne]

So that becomes:

target("cpp-lazy")
    set_kind("headeronly")
    add_includedirs("include", { public = true })
    add_packages("fmt", { public = true })
    add_headerfiles("include/(Lz/*.hpp)")
    add_headerfiles("include/(Lz/detail/*.hpp)")
target_end()

Do I also need to export fmt? Because now it fails on fmt:

C:\Users\marcd\AppData\Local\.xmake\packages\c\cpp-lazy\7.0.2\6fa98e054eb848d2b0c34c65e6efff2a\include\Lz\detail\LzTools.hpp(97): fatal error C1083: Cannot open include file: 'fmt/format.h': No such file or directory
  ${yellow}> in ${bright}C:\Users\marcd\AppData\Local\Temp\.xmake\230210\_0A8572B12ED84E3FB1FDE34F70EE1E33.cpp

[waruqi]

add_deps("fmt") in package cpp-lazy