libpng not linked on Mac OSX 10.9.2

Question

I installed matrix2png on my Mac and had used it without problem before last week when I installed another image manipulating tool "circos". Circos requires me to install a different version of libpng, and I did. After that, I am no longer able to run matrix2png, which gives me the following error. I think the old ligpnb is not linked any more. Does anyone know how to fix this error? - appreciate your help.

dyld: Library not loaded: /usr/local/lib/libpng15.15.dylib
  Referenced from: /usr/local/bin/matrix2png
  Reason: image not found

Answer 1

Those step solve my problem:

brew versions libpng

You will see some versions of libpng, but unfortunately not 1.5.15, so next you should install 1.5.18.

git checkout 7bec702 Library/Formula/libpng.rb
brew install libpng

You'll will find version 1.5.18 and some another versions.

ln -s /usr/local/Cellar/libpng/1.5.18/lib/libpng15.15.dylib /usr/local/lib/libpng15.15.dylib`

See https://github.com/Homebrew/homebrew-php/issues/1055

Some more info on installing certain versions of brew formulas can be found at https://coderwall.com/p/lqphzg.

Answer 2

Your new version of libpng has probably changed the name of its dyld files. This often happens with upgrades (especially following a major release). To verify this, open up the terminal and type:

ls /usr/local/lib/libpng*

What do you see?

From your error message we know that matrix2png is looking for libpng15 but if you've upgraded when instaling circos then you may now have libpng16 on your system. Consequently matrix2png won't be able to find the files that it's looking for and will be unhappy.

Fixing it this time:

Try re-installing matrix2png and see whether it notices the dependency issues and fixes it for you. You don't really want to downgrade libpng nor do you want to have two versions of it on your system, so having an up-to-date version of matrix2png would be good.

It looks like matrix2png comes from C source code, so you'll want to rebuild it. Download the source code or and then open a terminal. Navigate to the folder with the source code and run configure and then make. Configure will generate a Makefile for your system, and then make will use that file to generate a new binary. I've tested this on my Mac (with libpng16), and found that matrix2png built without any errors.

Suggested future approach:

To prevent future linking problems, you may want to use a package manager like homebrew or macports. In case you're using (or want to use) homebrew, it has circos and lib2png (but not matrix2png, sorry!). Once brew is installed, type the following into the terminal:

brew install libpng

And it should detect linking issues / version conflicts and guide you through fixing them. Brew places all of it's files in a 'cellar' location in /usr/local/Cellar and then symbolically links them into your system.

In case you're already using brew, try brew doctor and follow the instructions to resolve problems.

My experience (I've been dealing with a lot of version conflicts in the past few weeks) is that package managers make life much easier. Occasionally I've had to remove and reinstall packages to fix version issues, but in general brew keeps things neat and working.