Until now, ‘channel-build-system’ would assume a single channel, the
‘guix’ channel. This change lets users specify additional channels
using the #:channels parameter.
* guix/build-system/channel.scm (build-channels): Add #:channels and
honor it.
(channel-build-system): In ‘lower’, add #:channels and honor it.
* doc/guix.texi (Build Systems): Document it.
Change-Id: I36c1d19cbeee02a4d1144de089b78df0390774a0
This is a followup to cf60a0a906.
Reported by Mathieu Othacehe <othacehe@gnu.org>.
* guix/build-system/channel.scm (build-channels): Add 'string?' case.
* guix/build-system/channel.scm (latest-channel-instances*): New
variable.
(build-channels): New procedure, with code formerly in
'channel-build-system', augmented with clauses for when SOURCE is a
channel instance or a channel.
* doc/guix.texi (Build Systems): Adjust accordingly.
* gnu/ci.scm (channel-build-system, channel-source->package): Remove.
* gnu/packages/package-management.scm (channel-source->package): New
procedure, moved from (gnu ci).
* guix/build-system/channel.scm: New file, with code moved from (gnu ci).
* doc/guix.texi (Build Systems): Document it.
