On 21 Dec 2020, at 22:01, Michael wrote:
OK. Next question: Is there any reason I cannot install libpng version
15 at the sametime?
Not really. Better to update the software that wants it to use a current
version.
But the 1.5.x source is in the libpng site at Sourceforge, so you can
still get it, build it, and install the libraries where you need them
(/opt/X11/lib/)without affecting the v1.6.x version that MacPorts
installs.
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?
Yes and no. Versioned libraries exist because sometimes you really don't
want to link to anything but the version that you built against.
Sometimes interfaces change between versions, particularly "major"
version changes such as in this case, and software using the library may
be known to not be forward-compatible.
Also see below...
On 2020-12-21, at 6:55 PM, Ken Cunningham
<ken.cunningham.web...@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.
That's a bad sign, and a hint that you need to do more than just install
the right version of libpng.
The /opt/X11/ tree is where the "XQuartz" implementation of X11 installs
itself, along with a whole universe of its own required libraries. It
includes (in the last version, 2.7.11) 4 versions of libpng, with a
symlink for the unversioned name to libpng16.16.dylib. This implies
something of a mess in how the various binaries in the XQuartz package
were built, but you cannot fix that. You have a pre-built commercial
package that specifies at least one older version of a library as
installed by XQuartz so you can expect that it will also be dependent on
the whole collection of libraries installed by XQuartz.
If you lack /opt/X11/, you do not have XQuartz installed. Apple has not
included ANY X implementation in recent macOS versions, so you will need
to install XQuartz if you can't get a version of the failing software
built to use the X implementation that is installed by MacPorts.
--
Bill Cole
b...@scconsult.com or billc...@apache.org
(AKA @grumpybozo and many *@billmail.scconsult.com addresses)
Not Currently Available For Hire
