ci: Remove hydra support.

This removes hydra support to use Cuirass as the only continuous integration
system.

* build-aux/hydra/gnu-system.scm: Remove it.
* build-aux/hydra/guix-modular.scm: Ditto.
* build-aux/hydra/guix.scm: Ditto.
* build-aux/cuirass/hydra-to-cuirass.scm: Ditto.
* Makefile.am (EXTRA_DIST): Update it.
(hydra-jobs.scm): Remove it.
(cuirass-jobs.scm): Update it.
* build-aux/hydra/evaluate.scm: Move it to ...
* build-aux/cuirass/evaluate.scm: ... here.
* build-aux/cuirass/guix-modular.scm: Remove it.
* build-aux/cuirass/gnu-system.scm: Ditto.
* guix/packages.scm (%hydra-supported-systems): Rename it to ...
(%cuirass-supported-systems): ... this variable.
* build-aux/check-final-inputs-self-contained: Adapt it.
* etc/release-manifest.scm: Ditto.
* gnu/ci.scm (package->alist): Remove it.
(derivation->job): New procedure.
(package-job, package-cross-job, cross-jobs, image-jobs, system-test-jobs,
tarball-jobs): Use it.
(guix-jobs): New procedure.
(hydra-jobs): Rename it to ...
(cuirass-jobs): ... this procedure.

1 files changed, 1 insertions, 1 deletions

diff --git a/etc/release-manifest.scm b/etc/release-manifest.scm
index da98d6e00b..a1f731a945 100644
--- a/etc/release-manifest.scm
+++ b/etc/release-manifest.scm
@@ -103,7 +103,7 @@ TARGET."
                       (if (string=? system "i586-gnu")
                           %base-packages/hurd
                           %base-packages)))
-               %hydra-supported-systems)))
+               %cuirass-supported-systems)))
 
 (define %system-manifest
   (manifest