[BioC] getBioC() -- keeps grabbing everything

[Richard Finney]

Previously I have been using R Version 2.0.1 on a
Linux box as root and everything worked well.

I have installed in my local user director the latest
R Version 2.1.1 on a different machine (a Sun box)
from the source code and I am not running as root.  I
can't quite figure out how to make getBioC() not
constantly rebuild/reinstall the entire Bioconductor
Affy suite every time.

I do the 
"source ("http://www.bioconductor.org/getBioC.R")
and 
"getBioc("affy") 
and it always re-gets it; unlike
on the Linux box as root where it just said "
all requested packages are up to date".

I have fiddled with the lib argument to getBioC() and
I have set the R_HOME and R_LIB environment variables.
There may be an subtle incantation I need but can't
quite figure out.  

Anybody got any ideas?  How do you force the darn
thing to recognize that it has built the thing before?