The test for union semun requires <sys/ipc.h>

Pointed out by Bruce

src/configure

@@ -2644,12 +2644,13 @@ cat > conftest.$ac_ext <<EOF
 #line 2645 "configure"
 #include "confdefs.h"
 #include <sys/types.h>
+#include <sys/ipc.h>
 #include <sys/sem.h>
 int main() {
 union semun semun;
 ; return 0; }
 EOF
-if { (eval echo configure:2653: \"$ac_link\") 1>&5; (eval $ac_link) 2>&5; } && test -s conftest; then
+if { (eval echo configure:2654: \"$ac_link\") 1>&5; (eval $ac_link) 2>&5; } && test -s conftest; then
   rm -rf conftest*
   cat >> confdefs.h <<\EOF
 #define HAVE_UNION_SEMUN 1
@@ -2665,13 +2666,13 @@ rm -f conftest*
 
 if test $ac_cv_prog_gcc = yes; then
     echo $ac_n "checking whether ${CC-cc} needs -traditional""... $ac_c" 1>&6
-echo "configure:2669: checking whether ${CC-cc} needs -traditional" >&5
+echo "configure:2670: checking whether ${CC-cc} needs -traditional" >&5
 if eval "test \"`echo '$''{'ac_cv_prog_gcc_traditional'+set}'`\" = set"; then
   echo $ac_n "(cached) $ac_c" 1>&6
 else
     ac_pattern="Autoconf.*'x'"
   cat > conftest.$ac_ext <<EOF
-#line 2675 "configure"
+#line 2676 "configure"
 #include "confdefs.h"
 #include <sgtty.h>
 Autoconf TIOCGETP
@@ -2689,7 +2690,7 @@ rm -f conftest*
 
   if test $ac_cv_prog_gcc_traditional = no; then
     cat > conftest.$ac_ext <<EOF
-#line 2693 "configure"
+#line 2694 "configure"
 #include "confdefs.h"
 #include <termio.h>
 Autoconf TCGETA
@@ -2711,7 +2712,7 @@ echo "$ac_t""$ac_cv_prog_gcc_traditional" 1>&6
 fi
 
 echo $ac_n "checking for 8-bit clean memcmp""... $ac_c" 1>&6
-echo "configure:2715: checking for 8-bit clean memcmp" >&5
+echo "configure:2716: checking for 8-bit clean memcmp" >&5
 if eval "test \"`echo '$''{'ac_cv_func_memcmp_clean'+set}'`\" = set"; then
   echo $ac_n "(cached) $ac_c" 1>&6
 else
@@ -2719,7 +2720,7 @@ else
   ac_cv_func_memcmp_clean=no
 else
   cat > conftest.$ac_ext <<EOF
-#line 2723 "configure"
+#line 2724 "configure"
 #include "confdefs.h"
 
 main()
@@ -2729,7 +2730,7 @@ main()
 }
 
 EOF
-if { (eval echo configure:2733: \"$ac_link\") 1>&5; (eval $ac_link) 2>&5; } && test -s conftest && (./conftest; exit) 2>/dev/null
+if { (eval echo configure:2734: \"$ac_link\") 1>&5; (eval $ac_link) 2>&5; } && test -s conftest && (./conftest; exit) 2>/dev/null
 then
   ac_cv_func_memcmp_clean=yes
 else
@@ -2747,12 +2748,12 @@ echo "$ac_t""$ac_cv_func_memcmp_clean" 1>&6
 test $ac_cv_func_memcmp_clean = no && LIBOBJS="$LIBOBJS memcmp.o"
 
 echo $ac_n "checking return type of signal handlers""... $ac_c" 1>&6
-echo "configure:2751: checking return type of signal handlers" >&5
+echo "configure:2752: checking return type of signal handlers" >&5
 if eval "test \"`echo '$''{'ac_cv_type_signal'+set}'`\" = set"; then
   echo $ac_n "(cached) $ac_c" 1>&6
 else
   cat > conftest.$ac_ext <<EOF
-#line 2756 "configure"
+#line 2757 "configure"
 #include "confdefs.h"
 #include <sys/types.h>
 #include <signal.h>
@@ -2769,7 +2770,7 @@ int main() {
 int i;
 ; return 0; }
 EOF
-if { (eval echo configure:2773: \"$ac_compile\") 1>&5; (eval $ac_compile) 2>&5; }; then
+if { (eval echo configure:2774: \"$ac_compile\") 1>&5; (eval $ac_compile) 2>&5; }; then
   rm -rf conftest*
   ac_cv_type_signal=void
 else
@@ -2788,12 +2789,12 @@ EOF
 
 
 echo $ac_n "checking for vprintf""... $ac_c" 1>&6
-echo "configure:2792: checking for vprintf" >&5
+echo "configure:2793: checking for vprintf" >&5
 if eval "test \"`echo '$''{'ac_cv_func_vprintf'+set}'`\" = set"; then
   echo $ac_n "(cached) $ac_c" 1>&6
 else
   cat > conftest.$ac_ext <<EOF
-#line 2797 "configure"
+#line 2798 "configure"
 #include "confdefs.h"
 /* System header to define __stub macros and hopefully few prototypes,
     which can conflict with char vprintf(); below.  */
@@ -2816,7 +2817,7 @@ vprintf();
 
 ; return 0; }
 EOF
-if { (eval echo configure:2820: \"$ac_link\") 1>&5; (eval $ac_link) 2>&5; } && test -s conftest; then
+if { (eval echo configure:2821: \"$ac_link\") 1>&5; (eval $ac_link) 2>&5; } && test -s conftest; then
   rm -rf conftest*
   eval "ac_cv_func_vprintf=yes"
 else
@@ -2840,12 +2841,12 @@ fi
 
 if test "$ac_cv_func_vprintf" != yes; then
 echo $ac_n "checking for _doprnt""... $ac_c" 1>&6
-echo "configure:2844: checking for _doprnt" >&5
+echo "configure:2845: checking for _doprnt" >&5
 if eval "test \"`echo '$''{'ac_cv_func__doprnt'+set}'`\" = set"; then
   echo $ac_n "(cached) $ac_c" 1>&6
 else
   cat > conftest.$ac_ext <<EOF
-#line 2849 "configure"
+#line 2850 "configure"
 #include "confdefs.h"
 /* System header to define __stub macros and hopefully few prototypes,
     which can conflict with char _doprnt(); below.  */
@@ -2868,7 +2869,7 @@ _doprnt();
 
 ; return 0; }
 EOF
-if { (eval echo configure:2872: \"$ac_link\") 1>&5; (eval $ac_link) 2>&5; } && test -s conftest; then
+if { (eval echo configure:2873: \"$ac_link\") 1>&5; (eval $ac_link) 2>&5; } && test -s conftest; then
   rm -rf conftest*
   eval "ac_cv_func__doprnt=yes"
 else
@@ -2895,12 +2896,12 @@ fi
 for ac_func in isinf tzset getrusage vfork memmove sigsetjmp kill sysconf
 do
 echo $ac_n "checking for $ac_func""... $ac_c" 1>&6
-echo "configure:2899: checking for $ac_func" >&5
+echo "configure:2900: checking for $ac_func" >&5
 if eval "test \"`echo '$''{'ac_cv_func_$ac_func'+set}'`\" = set"; then
   echo $ac_n "(cached) $ac_c" 1>&6
 else
   cat > conftest.$ac_ext <<EOF
-#line 2904 "configure"
+#line 2905 "configure"
 #include "confdefs.h"
 /* System header to define __stub macros and hopefully few prototypes,
     which can conflict with char $ac_func(); below.  */
@@ -2923,7 +2924,7 @@ $ac_func();
 
 ; return 0; }
 EOF
-if { (eval echo configure:2927: \"$ac_link\") 1>&5; (eval $ac_link) 2>&5; } && test -s conftest; then
+if { (eval echo configure:2928: \"$ac_link\") 1>&5; (eval $ac_link) 2>&5; } && test -s conftest; then
   rm -rf conftest*
   eval "ac_cv_func_$ac_func=yes"
 else
@@ -2948,12 +2949,12 @@ fi
 done
 
 echo $ac_n "checking for inet_aton""... $ac_c" 1>&6
-echo "configure:2952: checking for inet_aton" >&5
+echo "configure:2953: checking for inet_aton" >&5
 if eval "test \"`echo '$''{'ac_cv_func_inet_aton'+set}'`\" = set"; then
   echo $ac_n "(cached) $ac_c" 1>&6
 else
   cat > conftest.$ac_ext <<EOF
-#line 2957 "configure"
+#line 2958 "configure"
 #include "confdefs.h"
 /* System header to define __stub macros and hopefully few prototypes,
     which can conflict with char inet_aton(); below.  */
@@ -2976,7 +2977,7 @@ inet_aton();
 
 ; return 0; }
 EOF
-if { (eval echo configure:2980: \"$ac_link\") 1>&5; (eval $ac_link) 2>&5; } && test -s conftest; then
+if { (eval echo configure:2981: \"$ac_link\") 1>&5; (eval $ac_link) 2>&5; } && test -s conftest; then
   rm -rf conftest*
   eval "ac_cv_func_inet_aton=yes"
 else
@@ -3001,12 +3002,12 @@ fi
 
 
 echo $ac_n "checking for cbrt""... $ac_c" 1>&6
-echo "configure:3005: checking for cbrt" >&5
+echo "configure:3006: checking for cbrt" >&5
 if eval "test \"`echo '$''{'ac_cv_func_cbrt'+set}'`\" = set"; then
   echo $ac_n "(cached) $ac_c" 1>&6
 else
   cat > conftest.$ac_ext <<EOF
-#line 3010 "configure"
+#line 3011 "configure"
 #include "confdefs.h"
 /* System header to define __stub macros and hopefully few prototypes,
     which can conflict with char cbrt(); below.  */
@@ -3029,7 +3030,7 @@ cbrt();
 
 ; return 0; }
 EOF
-if { (eval echo configure:3033: \"$ac_link\") 1>&5; (eval $ac_link) 2>&5; } && test -s conftest; then
+if { (eval echo configure:3034: \"$ac_link\") 1>&5; (eval $ac_link) 2>&5; } && test -s conftest; then
   rm -rf conftest*
   eval "ac_cv_func_cbrt=yes"
 else
@@ -3050,7 +3051,7 @@ EOF
 else
   echo "$ac_t""no" 1>&6
 echo $ac_n "checking for cbrt in -lm""... $ac_c" 1>&6
-echo "configure:3054: checking for cbrt in -lm" >&5
+echo "configure:3055: checking for cbrt in -lm" >&5
 ac_lib_var=`echo m'_'cbrt | sed 'y%./+-%__p_%'`
 if eval "test \"`echo '$''{'ac_cv_lib_$ac_lib_var'+set}'`\" = set"; then
   echo $ac_n "(cached) $ac_c" 1>&6
@@ -3058,7 +3059,7 @@ else
   ac_save_LIBS="$LIBS"
 LIBS="-lm  $LIBS"
 cat > conftest.$ac_ext <<EOF
-#line 3062 "configure"
+#line 3063 "configure"
 #include "confdefs.h"
 /* Override any gcc2 internal prototype to avoid an error.  */
 /* We use char because int might match the return type of a gcc2
@@ -3069,7 +3070,7 @@ int main() {
 cbrt()
 ; return 0; }
 EOF
-if { (eval echo configure:3073: \"$ac_link\") 1>&5; (eval $ac_link) 2>&5; } && test -s conftest; then
+if { (eval echo configure:3074: \"$ac_link\") 1>&5; (eval $ac_link) 2>&5; } && test -s conftest; then
   rm -rf conftest*
   eval "ac_cv_lib_$ac_lib_var=yes"
 else
@@ -3095,12 +3096,12 @@ fi
 fi
 
 echo $ac_n "checking for rint""... $ac_c" 1>&6
-echo "configure:3099: checking for rint" >&5
+echo "configure:3100: checking for rint" >&5
 if eval "test \"`echo '$''{'ac_cv_func_rint'+set}'`\" = set"; then
   echo $ac_n "(cached) $ac_c" 1>&6
 else
   cat > conftest.$ac_ext <<EOF
-#line 3104 "configure"
+#line 3105 "configure"
 #include "confdefs.h"
 /* System header to define __stub macros and hopefully few prototypes,
     which can conflict with char rint(); below.  */
@@ -3123,7 +3124,7 @@ rint();
 
 ; return 0; }
 EOF
-if { (eval echo configure:3127: \"$ac_link\") 1>&5; (eval $ac_link) 2>&5; } && test -s conftest; then
+if { (eval echo configure:3128: \"$ac_link\") 1>&5; (eval $ac_link) 2>&5; } && test -s conftest; then
   rm -rf conftest*
   eval "ac_cv_func_rint=yes"
 else
@@ -3144,7 +3145,7 @@ EOF
 else
   echo "$ac_t""no" 1>&6
 echo $ac_n "checking for rint in -lm""... $ac_c" 1>&6
-echo "configure:3148: checking for rint in -lm" >&5
+echo "configure:3149: checking for rint in -lm" >&5
 ac_lib_var=`echo m'_'rint | sed 'y%./+-%__p_%'`
 if eval "test \"`echo '$''{'ac_cv_lib_$ac_lib_var'+set}'`\" = set"; then
   echo $ac_n "(cached) $ac_c" 1>&6
@@ -3152,7 +3153,7 @@ else
   ac_save_LIBS="$LIBS"
 LIBS="-lm  $LIBS"
 cat > conftest.$ac_ext <<EOF
-#line 3156 "configure"
+#line 3157 "configure"
 #include "confdefs.h"
 /* Override any gcc2 internal prototype to avoid an error.  */
 /* We use char because int might match the return type of a gcc2
@@ -3163,7 +3164,7 @@ int main() {
 rint()
 ; return 0; }
 EOF
-if { (eval echo configure:3167: \"$ac_link\") 1>&5; (eval $ac_link) 2>&5; } && test -s conftest; then
+if { (eval echo configure:3168: \"$ac_link\") 1>&5; (eval $ac_link) 2>&5; } && test -s conftest; then
   rm -rf conftest*
   eval "ac_cv_lib_$ac_lib_var=yes"
 else

src/configure.in

@@ -141,6 +141,7 @@ AC_TRY_LINK([#include <time.h>],
 
 AC_MSG_CHECKING(for union semun)
 AC_TRY_LINK([#include <sys/types.h>
+#include <sys/ipc.h>
 #include <sys/sem.h>],
             [union semun semun;],
             [AC_DEFINE(HAVE_UNION_SEMUN) AC_MSG_RESULT(yes)],