Hi @f-scholer

Thanks for your report.
It seems that the missing bit in cmake-conan would be the definition of rc compiler, but I am confused that you tried to specify it, and it didn't work. Was the output error exactly the same when adding rc to compiler_executables?

Ok, I just realized. The openssl recipe uses the AutotoolsToolchain that defines the compiler mapping as: compilers_mapping = {"c": "CC", "cpp": "CXX", "cuda": "NVCC", "fortran": "FC"}

In other words, it is not prepared for cross-compiling from Linux -> Windows and defining the RC compiler.

So the issue needs to be addressed in both places, opening another ticket in the Conan client

In the meantime, you can define a profile with just the [buildenv] section, and pass it to your build as defined in the readme -DCONAN_HOST_PROFILE="default;custom"

Thanks for the quick action and suggestion. That works.

I had modified conan_provider.cmake to write the buildenv entries:
macro(append_buildenv_configuration)
if(CMAKE_C_COMPILER)
string(APPEND PROFILE "CC=${CMAKE_C_COMPILER}\n")
endif()
if(CMAKE_CXX_COMPILER)
string(APPEND PROFILE "CXX=${CMAKE_CXX_COMPILER}\n")
endif()
if(CMAKE_RC_COMPILER)
string(APPEND PROFILE "RC=${CMAKE_RC_COMPILER}\n")
endif()
endmacro()
...
string(APPEND PROFILE "[buildenv]\n")

propagate compilers

append_buildenv_configuration()

conan-io/conan#15946 has been merged it will be in the next Conan 2.3 release