Surprising dependency on WolfSSL and OpenSSL

[akrzemi1]

When following instructions in README.md:

include(FetchContent)
FetchContent_Declare(corosio
    GIT_REPOSITORY https://github.com/cppalliance/corosio.git
    GIT_TAG develop
    GIT_SHALLOW TRUE)
FetchContent_MakeAvailable(corosio)

target_link_libraries(my_app Boost::corosio)

I get the following error:

-- Fetching capy...
-- Could NOT find WolfSSL (missing: WolfSSL_INCLUDE_DIR WolfSSL_LIBRARY)
-- Could NOT find OpenSSL, try to set the path to OpenSSL root folder in the system variable OPENSSL_ROOT_DIR (missing: OPENSSL_CRYPTO_LIBRARY OPENSSL_INCLUDE_DIR)
CMake Error at CMakeLists.txt:30 (target_link_libraries):
  The keyword signature for target_link_libraries has already been used with
  the target "capy_test".  All uses of target_link_libraries with a target
  must be either all-keyword or all-plain.

  The uses of the keyword signature are here:

   * CMakeLists.txt:29 (target_link_libraries)



-- Configuring incomplete, errors occurred!
gmake: *** [Makefile:272: cmake_check_build_system] Error 1

Apparently, there is an undocumented dependency on WolfSSL and OpenSSL, and the instructions fail to account for them.

[LegalizeAdulthood]

This feels like a bug in the CMake logic; previously it was possible to build without either of these libraries.

[vinniefalco]

Corosio's build scripts are supposed to produce three targets:

corosio.lib // the main library
corosio_openssl.lib // the openssl integration, if OpenSSL is found
corosio_wolfssl.lib // the wolfssl integration, if WolfSSL is found

Our libraries (all my libraries) do not use configuration macros. There must never be a macro which, when defined, produces a different lib file. Instead, we create a separate build target and make that target conditional on the availability of the external dependency.

If it doesn't work this way, its a bug (and it seems like it doesn't work now).

[sgerbino]

I don't think this error is related to WolfSSL or OpenSSL. What is the target capy_test? Is that from your CMakeLists.txt?