Use of --prefix doesn't prevent creation of /usr/local/include/boost

[Braden McDaniel <braden@…>]

When building with:

$ ./bjam --prefix=$HOME --layout=system variant=release link=shared threading=multi -d+2 -q install

... I'm seeing:

common.mkdir /usr/local/include/boost

        mkdir -p "/usr/local/include/boost"
    
mkdir: cannot create directory `/usr/local/include/boost': Permission denied

Given that --prefix has been set to $HOME, it seems like an error that the build is even trying to create /usr/local/include/boost.

[Vladimir Prus]

This is fixed in SVN HEAD and release branch.