Building sandbox library (chrono)

I can't figure out how to build chrono. Here's what I did:

svn co http://svn.boost.org/svn/boost/trunk boost
svn co -N http://svn.boost.org/svn/boost/sandbox boost-sandbox
svn co http://svn.boost.org/svn/boost/sandbox/chrono boost-sandbox/chrono
cd boost
./configure
cd ../boost-sandbox/chrono/libs/chrono/test
../../../../../boost/tools/jam/src/bin.qnxntox86/bjam

I get:
error: Could not find parent for project at '../../../..'
error: Did not find Jamfile.jam or Jamroot.jam in any parent directory.

I have no clue how to create a Jamroot.jam if that's what I need to do.

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Regards

Niklas Angare