Greetings, It seems that SL4's gcc4-c++ package ("GCC version 4.1 preview") doesn't install gcc 4.1's include files, but instead g++4 is configured to use gcc3.4.3's include files ("g++4 -v" reports the "--with-gxx-include-dir=/usr/include/c++/3.4.3" option was used). This causes an enormous quantity of dire warning messages from various standard library classes (including <string>) when compiling almost anything with -O2 (such as CLHEP2 uses by default). These warnings are all to the effect that "dereferencing type-punned pointer will break strict-aliasing rules." This almost seems like it might be a mistake, and it is actually a problem for me, as my whole reason for trying to compare gcc4 and gcc3.4.3 was to try to diagnose a discrepancy we think we're seeing in the behavior of a Geant4 simulation compiled with gcc4 on one system vs. gcc3.4.3 on another. In particular, I've become somewhat suspicious of the type-punning in CLHEP2 because of a number of gcc bug reports of incorrect code being generated by gcc4.1 due to incorrect strict-aliasing optimizations. But with g++4 configured to use a standard template library that's not compatible with g++4, I don't see there's much point in proceeding with it as is. So, my question: is it possible to get gcc4* rpms for SL4 which install and use /usr/include/c++/4.1.1? (Also the corresponding version of libstdc++, for that matter.) If yes, it will save me some work; if not, I guess I'll have to install GCC4 from source if I want to make the comparison. Best regards, -Glenn Horton-Smith