Thanks @SSX. I created a Troubleshooting section on the wiki and have your answer posted there for the time being. It could be updated once this issue is fixed.
I thought about suppressing the warning while running the cmake command with the suppressing flag passed in (which will affect the whole project build). Modifying just the AI/FuzzyLite/fuzzylite/CMakeLists.txt is definitely a better solution given it only affects that particular subdirectory.
I found out the issue was caused by the SDL2_image files I previously installed under directory /LIbrary/Frameworks/SDL2_image.framework/Versions/A/SDL2_image. I removed this package (because I have no other pass depends on it).
After that, if I do otool -L vcmiclient, then the path to SDL2_image will be the correct one installed by homebrew:
I didn’t have to solve this at all. I suppose it’s related to the fact how packages are installed on your system. Did you manually changed where homebrew install packages by default? Since I think it’s /usr/local/Cellar always.
And how did you get SDL2 inside /Library/Frameworks/?
PS: Just in case there is one more relevant bug: #2771
It’s can be bypassed by removing assert, but shouldn’t be the problem anyway if you use older Clang too.