[Boost-build] --hash option undocumented?

Subject: [Boost-build] --hash option undocumented?
From: John Maddock (boost.regex_at_[hidden])
Date: 2012-10-19 07:58:44

I've just had a very capricious issue with path names exceeding the system 
maximum which caused doxygen to produce truncated output (it didn't fail 
though, it actually looked like an xsltproc failure later).  Once I realized 
what the issue was I knew there was a bjam option to shorten the path names, 
but I haven't been able to find it in the docs, or in the output of 
bjam --help.  I had to search the mailing to eventually track it down :-(

So can we please:

1) Document this somewhere.
2) Add it to bjam's --help output.
3) Is there any way that Boost.Build can detect over long paths up front and 
at least warn you about this issue?  It can take an awful long time to track 
down the cause if you're not expecting it.

Thanks, John.