I’m betting some kind of initialization, but do you use multiple threads? You may have to use GDK_THREADS_ENTER()/GDK_THREADS_LEAVE(); note that GTK /GDK are not thread-safe, they’re only thread-aware.

a) I know what all of the assertions mean, literally. I can’t figure out what is causing them though.
b) The test code (which is a c program) works well both when compiled in a plain c prog as well as a Qt wrapper with a GUI thread and all.
c) Seems like I’m going to have to run through valgrind.
d) @pfee: I like your suggestion, but this seems like a very arduous task considering the size of an application like Amarok.

Do you use a 64-bit setup? If so, make sure that those NULLs are being cast into a pointer type and see if that changes anything. Recent glibcs should automatically use the gcc-extension null pointer instead of 0 which means this shouldn’t be an issue but you never know.

If it still doesn’t work, try compiling the testcase in C mode instead of using C and see if it crashes. If so, the problem is a difference between C and C compilation.

> assertion `src != NULL’ failed
This means that src == NULL. Perhaps src needs to be initialized somewhere.

> g_object_unref: assertion `G_IS_OBJECT (object)’ failed
G_IS_OBJECT, if I’m reading this correctly, checks if a certain value is, in fact, a GObject. Perhaps the value is again NULL?

Did you remember to call the needed “G-initializers”?

gtk_init(&argc, &argv);

and maybe

g_threads_init(NULL);

Does some instance of a class need new-ing, and you are using an uninitialised version of the object.

Your first error says (to me) you do NOT have a buffer or source file open for the library to use or read.

Is something initialised and memory allocated in one thread or process, to which another thread or process does not have access to?

The second error, suggests that some incorrect object (or NULL) has been cast into the object reference, and perhaps does not supply a property or method needed.

The third error says your image buffer is the wrong size, it seems to suggest that you do not have an image buffer or your image is a different type/size to the one the image buffer was created for. I would expect an RGB image for static artwork.

On line 28 of your snippet, what if the file was not opened? Would it return NULL? Your seem to be checking pixbuf, but not filename.

ldd will show immediate dependencies, but libraries loaded via dlopen() won’t be shown. For that, lsof may help.

Armed with a list of libraries, you could use nm to find the symbols in each library, then look for duplicates.

Multiple similarly named libraries or duplicate symbols would be suspicious and may be your problem.

Hope that helps.