Hi,

Over the last week I tried to fetch substitutes with no success from
hydra.gnu.org.  It always showed the error "server is unresponsive".
However, the nar packages get downloaded with wget.

So, I removed the timeout with the attached patch and the substitute
downloads are working again.  This time I observed that the speed at
which the substitute-binary.scm downloads the nar file is far low than
when the same file is downloaded through wget.  I haven't done extensive
testing on this to confirm firmly, but it looks like the http-fetch
implementation is not efficient.  Can anyone confirm this?

-
Sree