Mac OS X - Linking executable to different dynamic library, load both old and new

Question

I've a command line tool, I built with Xcode, that links to some Apple frameworks.

As a "personal experiment" (just trying to understand a little of how dynamic libraries works) I tried to point the executable to a different version of the same frameworks.

Let's say for example that the executable EXEC uses LIB_A and the latter makes use of LIB_B.

I've made a copy of both LIB_A and LIB_B placing them under a different (shorter) directory path.

I used otool -L to get the dependencies and the ids of the libraries.

I then used install_name_tool with directive -id to change ids of new LIB_A and LIB_B (basically just changing the leading path as the name didn't changed).

Then with directive -change I let the new LIB_A to point to the new LIB_B and to let the executable EXEC to point to the new LIB_A.

This way, I thought, the whole dependency tree should have been correctly recreated.

---

install_name_tool didn't returned errors and inspecting the executable and the new libraries with otool they all point to the right path.

Unfortunately running the executable EXEC many errors are thrown to the console regarding duplicate definition of classes. Just as the old libraries and the new ones were loaded both.

Finally everything crash with Trace/BPT trap: 5

For example:

objc[25992]: Class NSAppleEventManager is implemented in both 
             /System/Library/Frameworks/Foundation.framework/Versions/C/Foundation and
             /xyz/Foundation.
             One of the two will be used. Which one is undefined.

If I invoke

export DYLD_PRINT_LIBRARIES=1

I see at execution that actually libraries are loaded twice.

Answer 1

I actually solved the issue by brutally setting

export DYLD_LIBRARY_PATH=

That worked for my particular situation.