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Postings from December 2015
Hi, The Makefile.SH in perl contains some code that will in certain situations create a wrapper script called preload used during compilation. I think this is a) not needed b) doesn't really work how it's intended c) can cause problems. The point of the wrapper seems to be to make sure that during the compilation perl uses the newly compiled libperl and not a libperl that might be already installed on the system. However the Makefile is already setting LD_LIBRARY_PATH, so that should not happen. The LD_LIBRARY_PATH method is less problematic, as I'll explain below. The check whether this preload script gets used looks like this: if test -f $archlib/CORE/$libperl; then This check will only be true if the paths used in the newly compiled perl are the same as in the one already on the system. E.g. if there's a libperl on the system with prefix /usr and the newly compiled perl has prefix /usr/local the check will fail. It won't matter, because as explained above the whole thing isn't needed anyway. Finally why I actually found this and why I think it causes problems: I tried to compile Perl with Address Sanitizer. This can cause the compilation to fail if this preload script is created. The reason is that if you LD_PRELOAD a library that was build with address sanitizer and then call any executable not built with address sanitizer it will crash. This caused gcc to crash. This does not happen with the LD_LIBRARY_PATH, because then only the libraries needed will be preloaded. Conclusion: Please just remove this, I don't think it does any good and it can cause problems. See attached patch. -- Hanno Böck http://hboeck.de/ mail/jabber: hanno@hboeck.de GPG: BBB51E42Thread Next