Fix spec reading when restarting builds.

When "spawn-builds" is called to restart builds, the spec is not known,
preventing build products from being created as reported here:

https://issues.guix.gnu.org/42523

Fix this issue by reading the specification in database in
"set-build-successful!" procedure.

* src/cuirass/database.scm (db-get-specification): New exported procedure,
(db-get-specifications): add an optional name argument.
* tests/database.scm (db-get-specification): Add a corresponding test-case.
* src/cuirass/base.scm (set-build-successful!): Remove spec argument and read
it directly from database instead,
(update-build-statuses!): also remove spec argument, adapt
set-build-successful! call accordingly,
(spawn-builds): remove spec argument and adapt handle-build-event and
update-build-statuses! calls accordingly,
(handle-build-event): remove spec argument, adapt
set-build-successful! call accordingly,
(build-packages): remove spec argument, adapt spawn-builds call accordingly,
(process-specs): adapt build-packages call.

1 files changed, 4 insertions, 0 deletions

diff --git a/tests/database.scm b/tests/database.scm
index 98b5012..944e4bf 100644
--- a/tests/database.scm
+++ b/tests/database.scm
@@ -110,6 +110,10 @@ INSERT INTO Evaluations (specification, in_progress) VALUES (3, false);")
       (db-add-specification example-spec)
       (car (db-get-specifications))))
 
+  (test-equal "db-get-specification"
+    example-spec
+    (db-get-specification "guix"))
+
   (test-equal "db-add-build"
     #f
     (let ((build (make-dummy-build "/foo.drv")))