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, 2 insertions, 2 deletions

diff --git a/gnu/build/linux-container.scm b/gnu/build/linux-container.scm
index 72e3a45422..d11c49c0d8 100644
--- a/gnu/build/linux-container.scm
+++ b/gnu/build/linux-container.scm
@@ -404,7 +404,7 @@ load path must be adjusted as needed."
 
 (define (container-excursion pid thunk)
   "Run THUNK as a child process within the namespaces of process PID and
-return the exit status."
+return the exit status, an integer as returned by 'waitpid'."
   (define (namespace-file pid namespace)
     (string-append "/proc/" (number->string pid) "/ns/" namespace))
 
@@ -436,7 +436,7 @@ return the exit status."
     (pid
      (match (waitpid pid)
        ((_ . status)
-        (status:exit-val status))))))
+        status)))))
 
 (define (container-excursion* pid thunk)
   "Like 'container-excursion', but return the return value of THUNK."