container: Correctly report exit status.

* gnu/build/linux-container.scm (container-excursion): Return the raw
status value.
* tests/containers.scm ("container-excursion, same namespaces"): Add
'status:exit-val' call.
* guix/scripts/container/exec.scm (guix-container-exec): Correctly
handle the different cases.

1 files changed, 4 insertions, 3 deletions

diff --git a/tests/containers.scm b/tests/containers.scm
index 608902c41ad..1378b10f22b 100644
--- a/tests/containers.scm
+++ b/tests/containers.scm
@@ -203,9 +203,10 @@
   42
   ;; The parent and child are in the same namespaces.  'container-excursion'
   ;; should notice that and avoid calling 'setns' since that would fail.
-  (container-excursion (getpid)
-    (lambda ()
-      (primitive-exit 42))))
+  (status:exit-val
+   (container-excursion (getpid)
+     (lambda ()
+       (primitive-exit 42)))))
 
 (skip-if-unsupported)
 (test-assert "container-excursion*"