diff --git a/clisp-link.dif b/clisp-link.dif
index f2ae8f2..df9b1b6 100644
--- a/clisp-link.dif
+++ b/clisp-link.dif
@@ -1,6 +1,7 @@
 ---
  src/clisp-link.in |    2 +-
- 1 file changed, 1 insertion(+), 1 deletion(-)
+ src/lispbibl.d    |    4 +++-
+ 2 files changed, 4 insertions(+), 2 deletions(-)
 
 --- src/clisp-link.in
 +++ src/clisp-link.in	2016-11-29 12:56:40.625559126 +0000
@@ -24,3 +25,12 @@
  #endif
  /* Use 'uintX' and 'sintX' for Integers with approximately given width
   and a minumum of storage space. */
+@@ -11622,7 +11622,7 @@ re-enters the corresponding top-level lo
+ #define pushSTACK(obj)  (STACK_(-1) = (obj), STACK skipSTACKop -1)
+   /* Almost equivalent with *--STACK = obj  resp.  *STACK++ = obj  , but
+    Careful: first enter the object into STACK_(-1), THEN modify the STACK! */
+-#define popSTACK()  (STACK skipSTACKop 1, STACK_(-1))
++#define popSTACK()  ({STACK skipSTACKop 1; STACK_(-1);})
+ #define skipSTACK(n)  (STACK skipSTACKop (sintP)(n))
+ 
+ #if defined(GNU) && defined(M68K) && !defined(NO_ASM) && !defined(WIDE) && defined(STACK_register)
diff --git a/clisp.changes b/clisp.changes
index 1f0ed8c..cb7acee 100644
--- a/clisp.changes
+++ b/clisp.changes
@@ -1,3 +1,9 @@
+-------------------------------------------------------------------
+Fri Feb 10 08:52:25 UTC 2017 - werner@suse.de
+
+- Collect some informations on the build system for debugging
+  a random error on sockets during test suite
+
 -------------------------------------------------------------------
 Thu Jan 19 12:20:06 UTC 2017 - werner@suse.de
 
diff --git a/clisp.spec b/clisp.spec
index 21c34bc..e5b6fdd 100644
--- a/clisp.spec
+++ b/clisp.spec
@@ -67,6 +67,7 @@ BuildRequires:  gdbm-devel
 BuildRequires:  gtk2-devel
 BuildRequires:  libglade2-devel
 BuildRequires:  libsigsegv-devel
+BuildRequires:  net-tools
 BuildRequires:  openssl-devel
 BuildRequires:  pcre-devel
 BuildRequires:  postgresql-devel
@@ -274,13 +275,29 @@ tail -q -s 0.5 -f $SCREENLOG & pid=$!
 #
 # Stop tail
 #
+sleep 1
 kill $pid
 
 #
 # Check for errors
 #
-test -z "$(ls build/tests/*.erg 2>/dev/null)"
 
+check=no
+for err in build/tests/*.erg
+do
+    test -e "$err" || break
+    check=yes
+    cat $err
+done
+if test $check != no
+then
+    type -p uname   > /dev/null 2>&1 && uname -a || :
+    type -p netstat > /dev/null 2>&1 && netstat -i || :
+    type -p netstat > /dev/null 2>&1 && netstat -x || :
+    type -p ip > /dev/null 2>&1 && ip link || :
+    type -p ss > /dev/null 2>&1 && ss -x   || :
+fi
+#
 %install
 #
 # Clean