CMake Warning:
  Manually-specified variables were not used by the project:

    CMAKE_EXPORT_NO_PACKAGE_REGISTRY
    CMAKE_INSTALL_DATAROOTDIR
    CMAKE_INSTALL_LIBEXECDIR
    CMAKE_INSTALL_OLDINCLUDEDIR
    CMAKE_INSTALL_SBINDIR


/home/conan/w/cci_PR-4017/.conan/data/mailio/0.20.0/_/_/build/6a9f5fd73afae35ea71d760f616dc1b0b2caecce/source_subfolder/src/mime.cpp:820:17: warning: enumeration value 'END' not handled in switch [-Wswitch]
        switch (state)
                ^
1 warning generated.
[HOOK - conan-center.py] post_package(): ERROR: [PC-FILES (KB-H020)] The conan-center repository doesn't allow the packages to contain `pc` files. The packages have to be located using generators and the declared `cpp_info` information (https://github.com/conan-io/conan-center-index/blob/master/docs/error_knowledge_base.md#KB-H020) 
[HOOK - conan-center.py] post_package(): ERROR: [PC-FILES (KB-H020)] Found files: ./lib/pkgconfig/mailio.pc (https://github.com/conan-io/conan-center-index/blob/master/docs/error_knowledge_base.md#KB-H020) 
ERROR: [HOOK - conan-center.py] post_package(): Some checks failed running the hook, check the output