Using X11 for an older program

[Michael]

OK. Next question: Is there any reason I cannot install libpng version 15 at the sametime?

I am aware that there is a non-versioned link file, that the latest version of the dynamic library installs. That can stay at 16 where it belongs. I mean specifically having both the libpng15 and the libpng16 files.

I am very surprised at linking to a specific version of a dynamic library. This is actually commercial software, and it did not link to generic "libpng", nor to generic "libpng15" -- linking to a specific version of a dynamic library? Isn't the whole point of dynamic libraries that you don't get a single specific buggy version, but the latest non-buggy version?

On 2020-12-21, at 6:55 PM, Ken Cunningham <ken.cunningham.webuse at gmail.com> wrote:

>> 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? 
> 
> There are likely to be more libraries missing after you fix this one, but you can try.
> 
> EIther symlink a real library that is the same or as similar as you have into the position being looked for:
> 
> sudo ln -s /opt/local/lib/libpng16.16.dylib /opt/X11/lib/libpng15.15.dylib
> 
> or
> 
> use install_name_tool to change /opt/local/lib/libpng16.16.dylib to /opt/X11/lib/libpng15.15.dylib in your binary.
> 
> install_name_tool -change  /opt/local/lib/libpng16.16.dylib /opt/X11/lib/libpng15.15.dylib /path/to/my/binary
> 
> 
> You can see that there are many many ways this could break / not work at all. 
> 
> But it sometimes works, if you’re lucky, and the libraries are very close to what is being looked for.
> 
> K

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