conan | open source version of the Conan platform provides users

The library lacks c++20 support (see https://en.cppreference.com/w/cpp/memory/allocator/allocate)

You can, for now, opt for c++17 compilation. Also, see whether they know about this issue, and if not report it to the developers.

• I take it the sample is reduced, but it seems to me the literal ought to be narrow, or the fmt ought to be wformat
• It appears that Boost 1.76 doesn't have this problem so, try upgrading boost

The solution was actually quite simple and straight forward after I had removed the readonly flag from the file data.json (otherwise exporting will fail with "Permission denied", at least on Windows):

As you found out yourself for QtQuick you need at least qtdeclarative=True, you can also add these options for the controls library:

The package is okay, but your profile is misconfigured.

undefined reference to `YAML::LoadFile(std::__cxx11::basic_string const&)' collect2: error: ld returned 1 exit status

You have to update your libcxx setting:

Is there a possibility to install a conan package without requirements?

Yes, conan download command. It ignores settings.

conan download downloads a package, but won't install it, e.g. there is no info, where it's downloaded

Not really, it's installed as equal in conan data folder. To obtain any package path, you can run conan info --paths (see info), but info command will download package dependencies.

You have few options:

• Run conan downloadand copy what you need:

The question I ask now is how to remove the deployed data (from /usr/local/lib, ...) when uninstalling the Conan package?

There is no such feature. But, you can ask for it here. It's a bit complicated, as Conan would need to cache deployed paths.

So seems I need to run build/make to trigger this step. Is there a way to copy the file before run make but right after the compile_commands.json been generated?

No. CMake generates the compile_commands.json during the generation step which happens immediately after your CMake code runs (configure step) and before the generated build system runs (build step).

CMake has no features to execute arbitrary CMake code during generation.

Is there any linking sequence problem? I see that usockets links behind libuv, maybe we can try swap the sequence: to link usockets first.

You are using static linkage, and usockets depends on libuv, so swap the sequence will fix the problem.

Related questions:

Why does the order in which libraries are linked sometimes cause errors in GCC?

The thing is, that you have to set the path to the library file as the target_link_libraries argument.

According to the documentation, if you want to link the library, each argument of target_link_libraries can be:

• A library target name
• A full path to a library file (e.g. /usr/lib/foo.so)
• A plain library name (e.g. foo)

In your case I suggest you to add the complete path to the library.

I don't have all the code of your project, so I suggest you consider this minimal example: