Hi, Over on the Boost-Users mailinglist we have found that this environment variable (and perhaps unknown but maybe others) will cause bootstrap.sh / Jam failure during the Boost libraries compile and install. Heres the full thread: http://lists.boost.org/boost-users/2011/04/67716.php You (or Jam developement team) may wish to consider taking some kind of action to avoid this as VMS is a very common acronym for "Virtual Machines". Its usage elsewhere is widespread and certainly not Boost-specific. Other choices of course - maybe look towards documenting such usag(es) if they cannot be easily avoided. Or consider ways to detect / warn / clean out the users shell environment variables if they are conflicting. Sorry I cant help any further however as a new user I simply have no experience with the Boost library yet. Many thanks. dreamcat4 dreamcat4@gmail.com