When computing channel instance derivations.
This is useful when you want to generate compatible derivations that can be
run with a daemon that potentially doesn't support builtin builders that the
daemon you're using to generate the derivations has.
I'm looking at this in particular because I want to use this in the data
service, since it provides substitutes for derivations, and since these can be
built on other machines, it's useful to control which builtin builders they
depend on.
Fixes: <https://issues.guix.gnu.org/67250>.
* build-aux/build-self.scm (build-program): Accept
#:built-in-builders and pass along to port->connection or
open-connection as approriate.
(build): Accept and pass on #:built-in-builders.
* guix/channels.scm (build-from-source, build-channel-instance,
channel-instance-derivations, channel-instances->manifest,
channel-instances->derivation): Accept and pass on
#:built-in-builders.
Change-Id: I315c990de66c6f7dca25a859165a5568abe385ea
d82ac48b07