Using X11 for an older program

[Michael]

On 2020-12-21, at 10:55 AM, Michael <keybounce at gmail.com> wrote:

> This should be a simple one. I hope.
> 
> I just installed a program that was compiled against the release version of mac's X11. Crashes on startup with this:
> 
> dyld: launch, loading dependent libraries
> 
> Dyld Error Message:
> Library not loaded: /opt/X11/lib/libpng15.15.dylib
> 
> What symbolic links do I need? /opt has no X11 directory.

Ok, another question. I found this:

/opt/local/lib/libpng16.16.dylib

I cannot find the older version. What do I need to do to install both the current and the older version of this library at the same time?