Installing CrowCpp with submodules and Conan without using the Crow Conan package

This post is a part of TIL; a series containing short posts of lessons I've learned the hard way.

CrowCpp's conan package is, at the time of writing anyway, heavily out of date, which isn't great. There hasn't been a tagged version in ages either, so this isn't Conan's fault, but the problem is still a problem regardless of whose fault it is.

On the bright side, it isn't too bad to install. It's just unnecessarily convoluted due to CrowCpp not dealing with its own dependencies.

First of all, add CrowCpp as a submodule:

git submodule add https://github.com/CrowCpp/Crow

Then add these dependencies to conan_cmake_configure:

# Crow dependencies
asio/1.24.0
openssl/3.0.7 
zlib/1.2.13

asio and OpenSSL are the newest versions at the time of writing, while zlib uses the same version the Conan package for CrowCpp uses. These may need to be updated. As usual, not all of these are explicitly required if another package includes them. You can just piggyback off that version, and it'll be fine.

Then just the submdoule prior to add_submodule(src), or in general before the part of your CMake where you configure your executables:

# This enables the optional SSL and compression features.
set(CROW_FEATURES ssl compression)
add_submodule(Crow)

Linking is trivial, and is just a bog standard

target_link_libraries(target Crow::Crow)

And that's it. Their CMakeLists.txt conveniently configures include directories and asio linking.