binding socket fails when run under ptrace?

[Tom Horsley]

On Tue, 26 Jul 2011 14:54:18 +0100
Bryn M. Reeves wrote:

> As others have said, that's how rsh "security" "works" - if you need to strace
> the command as a non-root user you might be able to come up with something
> involving dropping the file capability and granting cap_net_bind_service to the
> user you need to strace as (obviously this grants that user the ability to bind
> any port they like but for debugging you might chose to allow that).

I was looking for that, but can't find the slightest shred of evidence
that a user can be granted a capability in any of the googling I have
done. All I can find is setcap for granting a file capability.