[question] What are the default values and settings for conan v2 and find_pakage on windows?

[mtunjic]

What is your question?

Hi,
I'm currently using conan 2.3.0 with cmake 3.28 on windows 11 and problem is:
in older conan version before 2.x find_package from CMakeLists.txt worked without problems if I didn't set anything in package_info: (conan.py). Now now I get messages that the library does not exist.

        Broken: 
        Default settings without  def package_info(self):  
	
        Works:
	self.cpp_info.set_property("cmake_file_name", "mylib")
        self.cpp_info.set_property("cmake_target_name", f"mylib::{mylib}")
        self.cpp_info.set_property("pkg_config_name",  "mylib")

	Works:
        self.cpp_info.system_libs = ["mylib"]

	Broken:
	self.cpp_info.libs = ["mylib"]

What is needed now and what is the minimum configuration for find_pakcage to work properly?
I apologize if it is documented somewhere, I did not find it.

Thanks,
Marko

Have you read the CONTRIBUTING guide?

• I've read the CONTRIBUTING guide

[memsharded]

Hi @mtunjic

Thanks for your question.

I am not sure where the issue could be. If you check with the default template:

conan new cmake_lib -d name=mypkg -d version=0.1
conan create .

Then you will see that self.cpp_info.libs = ["mypkg"] works fin in package_info() nothing else is needed, definitely not the set_property() or the system_libs.
So it might be something else in your specific CMakeLists.txt. Maybe if you can share a full reproducible example, we could check it.

[mtunjic]

Thanks @memsharded , here is my old conan.py file adopted to conan v2 which causes the problem and CMakeFile.txt

--- conan.py v2 -----------------

from os import path, getenv
from conan import ConanFile
from conan.tools.cmake import CMakeToolchain, CMake, cmake_layout, CMakeDeps
from conan.tools.files import copy, rmdir 
from conan.tools.scm import Git

required_conan_version = ">=2.0.0"

class MyLibConan(ConanFile):
    name = "mylib"
    license = "MIT"
    package_type = "library"
    author = "Marko"

    description = "MyLib library"
    topics = ("security", "basic", "openssl", "x509")
    settings = "os", "compiler", "build_type", "arch"
    options = {"shared": [True, False], "fPIC": [True, False]}
    default_options = {"shared": False, "fPIC": True}
    exports_sources = "*"
    revision_mode = "scm"

    def config_options(self):
        if self.settings.os == "Windows":
            self.options.rm_safe("fPIC")

    
    def configure(self):
        if self.options.shared:
            self.options.rm_safe("fPIC")
        self.settings.rm_safe("compiler.libcxx")
        self.settings.rm_safe("compiler.cppstd")


    def generate(self):
        deps = CMakeDeps(self)
        deps.generate()
        tc = CMakeToolchain(self)
        tc.generate()

    def build(self):
        cmake = CMake(self)
        cmake.configure()
        cmake.build()


    def package(self):
        copy(self, pattern="*.h", dst=path.join(self.package_folder, "include"), src=path.join(self.source_folder, "."))
        copy(self, pattern="*.inl", dst=path.join(self.package_folder, "include"), src=path.join(self.source_folder, "."))
        copy(self, pattern="*.dll", src=self.build_folder, dst=path.join(self.package_folder, "bin"), keep_path=False)
        copy(self, pattern="*.lib", src=self.build_folder, dst=path.join(self.package_folder, "lib"), keep_path=False)
        copy(self, pattern="*.dylib*", src=self.build_folder, dst=path.join(self.package_folder, "lib"), keep_path=False)
        copy(self, pattern="*.so", src=self.build_folder, dst=path.join(self.package_folder, "lib"), keep_path=False)
        copy(self, pattern="*.a", src=self.build_folder, dst=path.join(self.package_folder, "lib"), keep_path=False)


    def package_info(self):
        self.cpp_info.libs = ["mylib"]


    def requirements(self):
        self.requires("cpdk/[~8.0.0]@windows/stable")


    def set_version(self):
        git = Git(self)
        tag = git.run("describe --tags")
        self.version = tag

--- end conan.py v2 ------

---- Consumer app CMakeLists.txt -----

cmake_minimum_required(VERSION 3.15)
project(HelloConan CXX)

find_package(mylib CONFIG REQUIRED)

add_executable(HelloConan src/HelloConan.cpp src/main.cpp)

target_link_libraries(HelloConan fmt::fmt mylib::mylib)

install(TARGETS HelloConan DESTINATION "."
        RUNTIME DESTINATION bin
        ARCHIVE DESTINATION lib
        LIBRARY DESTINATION lib
        ) 
---- end CMakeLIst.txt -------

and command for create:
$ conan create . --name=mylib --user=windows --channel=stable -tf=  --build=missing

[memsharded]

Thanks for the feedback.

There are a couple of things that doesn't seem correct:

• name = "MyLib" is incorrect, as Conan 2 doesn't allow upper case names anymore. It will also conflict with command line --name= argument
• exports_sources = pattern="*" seems broken too.

The CMakeLists.txt you are sharing seems to be the one for the consumer of mylib, not the one for mylib

I am afraid that I am still missing some information. To have a reproducible example, it would be necessary to provide something that we can actually fully run on our side. As you have the cpdk dependency and I am also missing the files from the mylib repo, it is not possible to reproduce. This is why I was suggesting to start with the conan new cmake_lib template, it is fully working and fully self-contained, so it is very convenient to report things. You can also share a full .zip or a git repo URL with more code that would help to reproduce and understand.

Other feedback:

• self.requires("cpdk/[~8.0.0]@windows/stable") the windows as "user" seems not recommended. The user shouldn't be used for this, but to identify the organization/team. To model the different os, that is part of the binary model of Conan, packages shouldn't be called after an architecture, os, or any other input "settings"

[mtunjic]

It was lowercased I made mistake for example. Yes you are right cmake file is from consumer side.
Thanks for the suggestions, I'll try to make a smaller demo and put it in a zip. I think it's best that you can try it.