diff --git a/guix/build/julia-build-system.scm b/guix/build/julia-build-system.scm
index b0dac154e9..119a7fed65 100644
--- a/guix/build/julia-build-system.scm
+++ b/guix/build/julia-build-system.scm
@@ -153,7 +153,11 @@ (define* (link-depot #:key source inputs outputs
                           Base.SHA1(Pkg.GitTools.tree_hash(\".\"))))" uuid)))
          (slug (string-trim-right (get-string-all pipe))))
     ;; Few packages do not have the regular Project.toml file, then when they
-    ;; are propagated, dependencies do not find them and an raise error.
+    ;; are propagated, dependencies do not find them and an error is raised.
+    (let ((status (close-pipe pipe)))
+      (unless (zero? status)
+        (error "failed to compute package slug" status)))
+
     (unless (file-exists? "Project.toml")
         (julia-create-package-toml (getcwd)
                                    julia-package-name julia-package-uuid