Dear Sali Sene This observation may be useful, but probably is not definitive
If you were to attempt to build an GCC 4.2.4 based Ada compiler using GNAT 2007 as the bootstrap Ada compiler, you will observe segmentation faults during the construction. If you were to delete the linker included with GNAT 2007, you will observe that the construction proceeds moe or less successfully (there are other different surprises) Look at the versions of the linkage editor present on your computer. Look at the versions of the linkage editor used to prepare binaries and libraries downloaded Dave Lightstone
