Safely cleaning 'downloads'

[Gary Thomas <gary@mlbassoc.com>]

Over time, I tend to build in the same build tree many, many
times.  This leads to some really big trees as many things are
duplicated, especially in the 'downloads' directory.

I use local mirrors and hence my 'downloads' directory is
_mostly_ populated with symbolic links.  However, there are
also expanded SCM packages, e.g. git2/xxx

How can I safely clean up the 'downloads' directory?  I already
copy any created tarballs (I use BB_GENERATE_MIRROR_TARBALLS="1"
to preclude unneeded downloads) to my mirror, but I'd like to
periodically clean out the whole directory (without disturbing
my builds of course).  I've found out the hard way that just
emptying seems to be unsafe, at least for some recipes like
the [RaspberryPi] Linux kernel recipe which once built seems
to expect the expanded git2/xxx tree to remain.

Just trying to find ways to recover my lost GB...

Thanks for any ideas

-- 
------------------------------------------------------------
Gary Thomas                 |  Consulting for the
MLB Associates              |    Embedded world
------------------------------------------------------------