This analysis costed me several hours: Origin was that pdftex randomly crashed when reading pdf pictures. The cause is that the header file /usr/include/poppler/poppler-config.h does *not* define MULTITHREADED while on the other hand, MULTITHREADED is defined during compilation of the poppler library. In my particular case this causes that the poppler library will expect that the class GlobalParams (in GlobalParams.{h,cc}) contains certain private variables while on the other hand the application pdftex from texlive-core did not allocate space for that variables during instantiation of the GlobalParams class. The effect is that the memory reserved for this class was too small and everything can happen (usually the segfault happened already in the constructor by calling some fontconfig libraries; but fontconfig is ok - the problem is just that it allocates memory which by accident already overrides the data of the class). The solution is of course to make sure that poppler-config.h matches with the compile-time configuration of poppler; probably some cmake configuration needs to be fixed for this, I do not want to learn cmake and therefore cannot help with this. Of course, texlive-core (and probably also several other applications) need to be reemerged after fixing the header files.
*** This bug has been marked as a duplicate of bug 304407 ***
