Sun supplies both POSIX and non-POSIX versions of readdir_r, according to http://docs.sun.com/app/docs/doc/819-2243/readdir-3c?a=view. The compliant version is selected by defining _POSIX_PTHREAD_SEMANTICS. So it looks to me that the fix for ticket #1578 (which is reporting the bug that results when the non-POSIX version is used) is to define _POSIX_PTHREAD_SEMANTICS at the beginning of boost-root/libs/filesystem/src/operations.cpp. This will cause the POSIX version to be used. I don't have access to a Sun system so can't test that. There is also a small chance that the same macro is used on some other platform in a conflicting way. I'd appreciate it if someone with access to a Sun system could test this (using the program given in the #1578). If I don't hear anything in a day or so, I'll go ahead and make the change to the trunk. Thanks, --Beman