diff --git a/gnu/packages/engineering.scm b/gnu/packages/engineering.scm
index 52a925225..0356fbfe9 100644
--- a/gnu/packages/engineering.scm
+++ b/gnu/packages/engineering.scm
@@ -1180,6 +1180,9 @@ high-performance parallel differential evolution (DE) optimization algorithm.")
     (license license:gpl2+)))
 
 (define-public libngspice
+  ;; Note: The ngspice's build system does not allow us to build both the
+  ;; library and the executables in one go.  Thus, we have two packages.
+  ;; See <https://debbugs.gnu.org/cgi/bugreport.cgi?bug=27344#236>.
   (package
     (name "libngspice")
     (version "26")
@@ -1249,6 +1252,7 @@ an embedded event driven algorithm.")
                    license:public-domain)))) ; xspice
 
 (define-public ngspice
+  ;; The ngspice executables (see libngpsice above.)
   (package (inherit libngspice)
     (name "ngspice")
     (arguments
@@ -1265,12 +1269,12 @@ an embedded event driven algorithm.")
                #t))
            (add-after 'install 'delete-cmpp-dlmain
              (lambda* (#:key outputs #:allow-other-keys)
-             (for-each
-              (lambda (file)
+               (for-each (lambda (file)
                            (delete-file
                             (string-append (assoc-ref outputs "out")
                                            file)))
-              '("/bin/cmpp" "/share/ngspice/dlmain.c"))))
+                         '("/bin/cmpp" "/share/ngspice/dlmain.c"))
+               #t))
            (delete 'delete-program-manuals)
            (delete 'delete-script-files)))))
     (inputs