Small command-line program to update LC_VERSION_MIN_MACOSX to 10.9 if it is less than 10.9.
gcc fix_LC_VERSION_MIN_MACOSX.c -o fixMonoMinVersion
Run it on your application like this:
fixMonoMinVersion "${APP_PATH}/Contents/Frameworks/MonoEmbedRuntime/osx/libmono.0.dylib"
fixMonoMinVersion "${APP_PATH}/Contents/Frameworks/MonoEmbedRuntime/osx/libMonoPosixHelper.dylib"
This code came from a gist that no longer exists (https://gist.github.com/lynnlx/1c15f290383c750abdd9d42e70bd32e4).
The code from that gist seems to have be derived from this one.
Since I pointed to it in a blog post, I've created this repo to host the code.
For more information on what this does and when it is useful, please see the article Notarizing Older Unity Games On macOS.