--2013-09-30 16:23:25--  http://www.bioconductor.org/packages/2.9/bioc/src/contrib/rtracklayer_1.20.0.tar.gz
Resolving www.bioconductor.org... 54.230.120.66, 54.230.122.237, 54.240.170.46, ...
Connecting to www.bioconductor.org|54.230.120.66|:80... connected.
HTTP request sent, awaiting response... 404 Not Found
2013-09-30 16:23:25 ERROR 404: Not Found.