Installation using CMake on Ubuntu 22.04

[abhishek47kashyap]

I'm following instructions outlined here to install using CMake on Ubuntu 22.04. Note that catch2 version for Ubuntu 22.04 is 2.13.8-1 (source), which is the version number that shows up when I do apt info catch2.

cmake .. fails because tests requires version 3:

autodiff/tests/CMakeLists.txt

Line 2 in d97e7cf

find_package(Catch2 3 REQUIRED)

The error message is:

CMake Error at tests/CMakeLists.txt:2 (find_package):
  Could not find a configuration file for package "Catch2" that is compatible
  with requested version "3".

  The following configuration files were considered but not accepted:

    /usr/lib/cmake/Catch2/Catch2Config.cmake, version: 2.13.8
    /lib/cmake/Catch2/Catch2Config.cmake, version: 2.13.8

In my case catch2 has reverse dependencies so upgrading may very likely break other installed packages that require Ubuntu 22.04 as their platform.

Any recommendations on how to resolve this? Has anyone tried any solutions that worked for them? I'm eyeing FetchContent but that pulls a specific version (if I've understood how to use FetchContent_Declare correctly) and would require updating tests/CMakeLists.txt to keep up with newer releases.

[abhishek47kashyap]

Here's how I managed to make it work using FetchContent by replacing find_package(Catch2 3 REQUIRED) with the snippet below:

find_package(Catch2 3 QUIET)
if(Catch2_FOUND)
    find_package(Catch2 3 REQUIRED)
else()
    message(STATUS "Catch2 3 not found. Downloading source code..")
    
    # https://github.com/catchorg/Catch2/blob/devel/docs/cmake-integration.md#cmake-targets
    include(FetchContent)
    Set(FETCHCONTENT_QUIET FALSE)
    FetchContent_Declare(
        Catch2
        GIT_REPOSITORY "git@github.com:catchorg/Catch2.git"
        GIT_TAG "v3.5.2"
        GIT_PROGRESS TRUE
    )
    FetchContent_MakeAvailable(Catch2)
endif()

[abhishek47kashyap]

Needed to pay more attention to the installation guidelines, cmake stuff has to be done inside a conda environment

See #305 (comment)