diff --git a/C/absmi.c b/C/absmi.c
index 5094a2835..afd6bd509 100644
--- a/C/absmi.c
+++ b/C/absmi.c
@@ -299,7 +299,7 @@ absmi(int inp)
 #endif
       if (!growheap(FALSE)) {
 	saveregs();
-	Error(SYSTEM_ERROR, TermNil, "YAP failed to reserve space in growheap");
+	Error(SYSTEM_ERROR, TermNil, "YAP failed to grow heap: %s", ErrorMessage);
 	setregs();
 	FAIL();
       }
@@ -1918,7 +1918,9 @@ absmi(int inp)
       if (ASP > (CELL *)B)
 	ASP = (CELL *)B;
       saveregs();
-      gc(((PredEntry *)SREG)->ArityOfPE, Y, NEXTOP(PREG, sla));
+      if (!gc(((PredEntry *)SREG)->ArityOfPE, Y, NEXTOP(PREG, sla))) {
+	Error(OUT_OF_STACK_ERROR,TermNil,ErrorMessage);
+      }
       setregs();
 
       JMPNext();
@@ -1990,7 +1992,9 @@ absmi(int inp)
       if (ASP > (CELL *)B)
 	ASP = (CELL *)B;
       saveregs();
-      gc(0, Y, NEXTOP(PREG, sla));
+      if (!gc(0, Y, NEXTOP(PREG, sla))) {
+	Error(OUT_OF_STACK_ERROR,TermNil,ErrorMessage);
+      }
       setregs();
       JMPNext();
 
@@ -2072,7 +2076,9 @@ absmi(int inp)
       if (ASP > (CELL *)B)
 	ASP = (CELL *)B;
       saveregs();
-      gc(((PredEntry *)(SREG))->ArityOfPE, (CELL *)Y[E_E], (yamop *)Y[E_CP]);
+      if (!gc(((PredEntry *)(SREG))->ArityOfPE, (CELL *)Y[E_E], (yamop *)Y[E_CP])) {
+	Error(OUT_OF_STACK_ERROR,TermNil,ErrorMessage);
+      }
       setregs();
       /* hopefully, gc will succeeded, and we will retry
        * the instruction */
@@ -2086,7 +2092,9 @@ absmi(int inp)
       if (ASP > (CELL *)B)
 	ASP = (CELL *)B;
       saveregs();
-      gc(((PredEntry *)(SREG))->ArityOfPE, ENV, CPREG);
+      if (!gc(((PredEntry *)(SREG))->ArityOfPE, ENV, CPREG)) {
+	Error(OUT_OF_STACK_ERROR,TermNil,ErrorMessage);
+      }
       setregs();
       /* hopefully, gc will succeeded, and we will retry
        * the instruction */
@@ -10564,8 +10572,13 @@ absmi(int inp)
 	if (pt1+d1 > ENV || pt1+d1 > (CELL *)B) {
 	  /* make sure we have something to show for our trouble */
 	  saveregs();
-	  gc(0, Y, NEXTOP(NEXTOP(PREG,xxx),sla));
-	  setregs();
+	  if (!gc(0, Y, NEXTOP(NEXTOP(PREG,xxx),sla))) {
+	    Error(OUT_OF_STACK_ERROR,TermNil,ErrorMessage);
+	    setregs();
+	    JMPNext();
+	  } else {
+	    setregs();
+	  }
 	  goto restart_func2s;
 	}
 	while ((Int)d1--) {
@@ -10672,8 +10685,13 @@ absmi(int inp)
 	if (pt1+d1 > ENV || pt1+d1 > (CELL *)B) {
 	  /* make sure we have something to show for our trouble */
 	  saveregs();
-	  gc(0, Y, NEXTOP(NEXTOP(PREG,xcx),sla));
-	  setregs();
+	  if (!gc(0, Y, NEXTOP(NEXTOP(PREG,xcx),sla))) {
+	    Error(OUT_OF_STACK_ERROR,TermNil,ErrorMessage);
+	    setregs();
+	    JMPNext();
+	  } else {
+	    setregs();
+	  }
 	  goto restart_func2s_cv;
 	}
 	while ((Int)d1--) {
@@ -10777,8 +10795,13 @@ absmi(int inp)
       if (pt1+d1 > ENV || pt1+d1 > (CELL *)B) {
 	/* make sure we have something to show for our trouble */
 	saveregs();
-	gc(0, Y, NEXTOP(NEXTOP(PREG,xxc),sla));
-	setregs();
+	if (!gc(0, Y, NEXTOP(NEXTOP(PREG,xxc),sla))) {
+	  Error(OUT_OF_STACK_ERROR,TermNil,ErrorMessage);
+	  setregs();
+	  JMPNext();
+	} else {
+	  setregs();
+	}
 	goto restart_func2s_vc;
       }
       while ((Int)d1--) {
@@ -10879,8 +10902,13 @@ absmi(int inp)
 	if (pt1+d1 > ENV || pt1+d1 > (CELL *)B) {
 	  /* make sure we have something to show for our trouble */
 	  saveregs();
-	  gc(0, Y, NEXTOP(NEXTOP(PREG,yxx),sla));
-	  setregs();
+	  if (!gc(0, Y, NEXTOP(NEXTOP(PREG,yxx),sla))) {
+	    Error(OUT_OF_STACK_ERROR,TermNil,ErrorMessage);
+	    setregs();
+	    JMPNext();
+	  } else {
+	    setregs();
+	  }
 	  goto restart_func2s_y;
 	}
 	while ((Int)d1--) {
@@ -11009,8 +11037,13 @@ absmi(int inp)
 	if (pt1+d1 > ENV || pt1+d1 > (CELL *)B) {
 	  /* make sure we have something to show for our trouble */
 	  saveregs();
-	  gc(0, Y, NEXTOP(NEXTOP(PREG,ycx),sla));
-	  setregs();
+	  if (!gc(0, Y, NEXTOP(NEXTOP(PREG,ycx),sla))) {
+	    Error(OUT_OF_STACK_ERROR,TermNil,ErrorMessage);
+	    setregs();
+	    JMPNext();
+	  } else {
+	    setregs();
+	  }
 	  goto restart_func2s_y_cv;
 	}
 	while ((Int)d1--) {
@@ -11148,8 +11181,13 @@ absmi(int inp)
       if (pt1+d1 > ENV || pt1+d1 > (CELL *)B) {
 	/* make sure we have something to show for our trouble */
 	saveregs();
-	gc(0, Y, NEXTOP(NEXTOP(PREG,yxc),sla));
-	setregs();
+	if (!gc(0, Y, NEXTOP(NEXTOP(PREG,yxc),sla))) {
+	  Error(OUT_OF_STACK_ERROR,TermNil,ErrorMessage);
+	  setregs();
+	  JMPNext();
+	} else {
+	  setregs();
+	}
 	goto restart_func2s_y_vc;
       }
       while ((Int)d1--) {
@@ -11533,8 +11571,13 @@ absmi(int inp)
 	if (pt1+d1 > ENV || pt1+d1 > (CELL *)B) {
 	  /* make sure we have something to show for our trouble */
 	  saveregs();
-	  gc(3, Y, NEXTOP(NEXTOP(PREG,e),sla));
-	  setregs();
+	  if (!gc(3, Y, NEXTOP(NEXTOP(PREG,e),sla))) {
+	    Error(OUT_OF_STACK_ERROR,TermNil,ErrorMessage);
+	    setregs();
+	    JMPNext();
+	  } else {
+	    setregs();
+	  }
 	  goto restart_functor;
 	}
 	while ((Int)d1--) {
diff --git a/C/alloc.c b/C/alloc.c
index 8f9d18788..d354f418d 100644
--- a/C/alloc.c
+++ b/C/alloc.c
@@ -12,7 +12,7 @@
 * Last rev:								 *
 * mods:									 *
 * comments:	allocating space					 *
-* version:$Id: alloc.c,v 1.22 2002-09-02 17:33:00 vsc Exp $		 *
+* version:$Id: alloc.c,v 1.23 2002-10-10 05:58:48 vsc Exp $		 *
 *************************************************************************/
 #ifdef SCCS
 static char SccsId[] = "%W% %G%";
@@ -48,6 +48,15 @@ static char SccsId[] = "%W% %G%";
 #endif
 #endif
 
+#if !HAVE_SNPRINTF
+#define snprintf(A,B,C)  sprintf(A,C)
+#define snprintf(A,B,C,D)  sprintf(A,C,D)
+#define snprintf(A,B,C,D,E)  sprintf(A,C,D,E)
+#define snprintf(A,B,C,D,E,F)  sprintf(A,C,D,E,F)
+#define snprintf(A,B,C,D,E,F,G)  sprintf(A,C,D,E,F,G)
+#define snprintf(A,B,C,D,E,F,G,H)  sprintf(A,C,D,E,F,G,H)
+#endif
+
 STATIC_PROTO(void FreeBlock, (BlockHeader *));
 STATIC_PROTO(BlockHeader *GetBlock, (unsigned int));
 STATIC_PROTO(char *AllocHeap, (unsigned int));
@@ -390,12 +399,26 @@ int
 ExtendWorkSpace(Int s)
 {
   LPVOID b;
+  prolog_exec_mode OldPrologMode = PrologMode;
+
+  PrologMode = ExtendStackMode;
   s = ((s-1)/page_size+1)*page_size;
   b = VirtualAlloc(brk, s, MEM_COMMIT, PAGE_READWRITE);
   if (b) {
   	brk = (LPVOID) ((Int) brk + s);
+	PrologMode = OldPrologMode;
 	return TRUE;
   }
+  ErrorMessage = ErrorSay;
+#if HAVE_STRERROR
+  snprintf(ErrorMessage, MAX_ERROR_MSG_SIZE,
+	    "VirtualAlloc could not commit %ld bytes",
+	    s);
+#else
+  snprintf(ErrorMessage, MAX_ERROR_MSG_SIZE,
+	   "mkstemp could not create temporary file %s", file);
+#endif /* HAVE_STRERROR */
+  PrologMode = OldPrologMode;
   return FALSE;
 }
 
@@ -412,8 +435,8 @@ InitWorkSpace(Int s)
     YP_fprintf(YP_stderr,"[ Warning: YAP reserving space at a variable address ]\n");
     b = VirtualAlloc(0x0, MAX_WORKSPACE, MEM_RESERVE, PAGE_NOACCESS);
     if (b == NULL) {
-      YP_fprintf(YP_stderr,"[ FATAL ERROR: YAP failed to reserve space ]\n");
-      exit(1);
+      Error(FATAL_ERROR,"VirtualAlloc failed");
+      return(0);
     }
   }
   brk = BASE_ADDRESS;
@@ -421,8 +444,8 @@ InitWorkSpace(Int s)
   if (ExtendWorkSpace(s)) {
     return BASE_ADDRESS;
   } else {
-    YP_fprintf(YP_stderr,"[ FATAL ERROR: YAP failed to reserve space ]\n");
-    exit(1);
+    Error(FATAL_ERROR,"VirtualAlloc Failed");
+    return(0);
   }
 }
 
@@ -468,14 +491,14 @@ InitWorkSpace(Int s)
   a = mmap(((void *)MMAP_ADDR), (size_t) s, PROT_READ | PROT_WRITE | PROT_EXEC,
 	   MAP_PRIVATE | MAP_ANONYMOUS | MAP_FIXED, -1, 0);
   if (a != (MALLOC_T)MMAP_ADDR) {
-    Error(SYSTEM_ERROR, TermNil, "mmap could not map ANON at %p, got %p", (void *)MMAP_ADDR, a);
+    Error(FATAL_ERROR, TermNil, "mmap could not map ANON at %p, got %p", (void *)MMAP_ADDR, a);
     return(NULL);
   }
 #elif defined(__APPLE__)
   a = mmap(((void *)MMAP_ADDR), (size_t) s, PROT_READ | PROT_WRITE | PROT_EXEC,
 	   MAP_PRIVATE | MAP_ANON | MAP_FIXED, -1, 0);
   if (a != (MALLOC_T)MMAP_ADDR) {
-    Error(SYSTEM_ERROR, TermNil, "mmap could not map ANON at %p, got %p", (void *)MMAP_ADDR,a );
+    Error(FATAL_ERROR, TermNil, "mmap could not map ANON at %p, got %p", (void *)MMAP_ADDR,a );
     return(NULL);
   }
 #else
@@ -486,9 +509,9 @@ InitWorkSpace(Int s)
     strncpy(file,"/tmp/YAP.TMPXXXXXX", 256);
     if (mkstemp(file) == -1) {
 #if HAVE_STRERROR
-      Error(SYSTEM_ERROR, TermNil, "mkstemp could not create temporary file %s (%s)", file, strerror(errno));
+      Error(FATAL_ERROR, TermNil, "mkstemp could not create temporary file %s (%s)", file, strerror(errno));
 #else
-      Error(SYSTEM_ERROR, TermNil, "mkstemp could not create temporary file %s", file);
+      Error(FATAL_ERROR, TermNil, "mkstemp could not create temporary file %s", file);
 #endif
       return NULL;
     }
@@ -503,19 +526,22 @@ InitWorkSpace(Int s)
 #endif /* HAVE_MKSTEMP */
     fd = open(file, O_CREAT|O_RDWR);
     if (fd < 0) {
-      Error(SYSTEM_ERROR, TermNil, "mmap could not open %s", file);
+      Error(FATAL_ERROR, TermNil, "mmap could not open %s", file);
       return NULL;
     }
     if (lseek(fd, s, SEEK_SET) < 0) {
-      Error(SYSTEM_ERROR, TermNil, "mmap could not lseek in mmapped file %s", file);
+      Error(FATAL_ERROR, TermNil, "mmap could not lseek in mmapped file %s", file);
+      close(fd);
       return FALSE;
     }
     if (write(fd, "", 1) < 0) {
-      Error(SYSTEM_ERROR, TermNil, "mmap could not write in mmapped file %s", file);
+      Error(FATAL_ERROR, TermNil, "mmap could not write in mmapped file %s", file);
+      close(fd);
       return NULL;
     }
     if (unlink(file) < 0) {
-      Error(SYSTEM_ERROR,TermNil, "mmap could not unlink mmapped file %s", file);
+      Error(FATAL_ERROR,TermNil, "mmap could not unlink mmapped file %s", file);
+      close(fd);
       return NULL;
     }
   }
@@ -523,7 +549,7 @@ InitWorkSpace(Int s)
   a = mmap(((void *)MMAP_ADDR), (size_t) s, PROT_READ | PROT_WRITE | PROT_EXEC,
 	   MAP_PRIVATE | MAP_FIXED, fd, 0);
   if (a != (MALLOC_T)MMAP_ADDR) {
-    Error(SYSTEM_ERROR, TermNil, "mmap could not map at %p, got %p", (void *)MMAP_ADDR, a);
+    Error(FATAL_ERROR, TermNil, "mmap could not map at %p, got %p", (void *)MMAP_ADDR, a);
     return NULL;
   }
 #else
@@ -535,7 +561,7 @@ InitWorkSpace(Int s)
     return NULL;
   }
   if (close(fd) == -1) {
-    Error(SYSTEM_ERROR, TermNil, "while closing mmaped file");
+    Error(FATAL_ERROR, TermNil, "while closing mmaped file");
     return NULL;
   }
 #endif
@@ -563,27 +589,36 @@ ExtendWorkSpace(Int s)
 #else
 
   MALLOC_T a;
+  prolog_exec_mode OldPrologMode = PrologMode;
 
 #if defined(_AIX) || defined(__hpux)
+  PrologMode = ExtendStackMode;
   a = mmap(WorkSpaceTop, (size_t) s, PROT_READ | PROT_WRITE | PROT_EXEC,
 		    MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
 
 #elif defined(__APPLE__)
+  PrologMode = ExtendStackMode;
   a = mmap(WorkSpaceTop, (size_t) s, PROT_READ | PROT_WRITE | PROT_EXEC,
 		    MAP_PRIVATE | MAP_ANON | MAP_FIXED, -1, 0);
 #else
   int fd;
+  PrologMode = ExtendStackMode;
   fd = open("/dev/zero", O_RDWR);
   if (fd < 0) {
 #if HAVE_MKSTEMP
     char file[256];
     strncpy(file,"/tmp/YAP.TMPXXXXXX",256);
     if (mkstemp(file) == -1) {
+      ErrorMessage = ErrorSay;
 #if HAVE_STRERROR
-      Error(SYSTEM_ERROR, TermNil, "mkstemp could not create temporary file %s (%s)", file, strerror(errno));
+      snprintf(ErrorMessage, MAX_ERROR_MSG_SIZE,
+		"mkstemp could not create temporary file %s (%s)",
+		file, strerror(errno));
 #else
-      Error(SYSTEM_ERROR, TermNil, "mkstemp could not create temporary file %s", file);
+      snprintf(ErrorMessage, MAX_ERROR_MSG_SIZE,
+		"mkstemp could not create temporary file %s", file);
 #endif /* HAVE_STRERROR */
+      PrologMode = OldPrologMode;
       return FALSE;
     }
 #else
@@ -597,47 +632,79 @@ ExtendWorkSpace(Int s)
 #endif /* HAVE_MKSTEMP */
     fd = open(file, O_CREAT|O_RDWR);
     if (fd < 0) {
-      Error(SYSTEM_ERROR, TermNil, "mmap could not open %s", file);
+      ErrorMessage = ErrorSay;
+      snprintf(ErrorMessage, MAX_ERROR_MSG_SIZE,
+		"mmap could not open %s", file);
+      PrologMode = OldPrologMode;
       return FALSE;
     }
     if (lseek(fd, s, SEEK_SET) < 0) {
-      Error(SYSTEM_ERROR, TermNil, "mmap could not lseek in mmapped file %s", file);
+      ErrorMessage = ErrorSay;
+      snprintf(ErrorMessage, MAX_ERROR_MSG_SIZE,
+		"mmap could not lseek in mmapped file %s", file);
+      PrologMode = OldPrologMode;
+      close(fd);
       return FALSE;
     }
     if (write(fd, "", 1) < 0) {
-      Error(SYSTEM_ERROR, TermNil, "mmap could not write in mmapped file %s", file);
+      ErrorMessage = ErrorSay;
+      snprintf(ErrorMessage, MAX_ERROR_MSG_SIZE,
+		"mmap could not write in mmapped file %s", file);
+      PrologMode = OldPrologMode;
+      close(fd);
       return FALSE;
     }
     if (unlink(file) < 0) {
-      Error(SYSTEM_ERROR, TermNil, "mmap could not unlink mmapped file %s", file);
+      ErrorMessage = ErrorSay;
+      snprintf(ErrorMessage, MAX_ERROR_MSG_SIZE,
+		"mmap could not unlink mmapped file %s", file);
+      PrologMode = OldPrologMode;
+      close(fd);
       return FALSE;
     }
   }
   a = mmap(WorkSpaceTop, (size_t) s, PROT_READ | PROT_WRITE | PROT_EXEC,
-		    MAP_PRIVATE | MAP_FIXED, fd, 0);
-  if (close(fd) == -1) {
-#if HAVE_STRERROR
-    Error(SYSTEM_ERROR, TermNil, "mmap could not close file (%s) ]\n", strerror(errno));
-#else
-    Error(SYSTEM_ERROR, TermNil, "mmap could not close file ]\n");
+		    MAP_PRIVATE
+#ifndef __linux
+	   /* use  MAP_FIXED, otherwise God knows where you will be placed */
+	   |MAP_FIXED
 #endif
+	   , fd, 0);
+  if (close(fd) == -1) {
+    ErrorMessage = ErrorSay;
+#if HAVE_STRERROR
+    snprintf(ErrorMessage, MAX_ERROR_MSG_SIZE,
+	      "mmap could not close file (%s) ]\n", strerror(errno));
+#else
+    snprintf(ErrorMessage, MAX_ERROR_MSG_SIZE,
+	      "mmap could not close file ]\n");
+#endif
+    PrologMode = OldPrologMode;
     return FALSE;
   }
 #endif
   if (a == (MALLOC_T) - 1) {
+    ErrorMessage = ErrorSay;
 #if HAVE_STRERROR
-    Error(SYSTEM_ERROR, TermNil, "could not allocate %d bytes (%s)", (int)s, strerror(errno));
+    snprintf(ErrorMessage, MAX_ERROR_MSG_SIZE,
+	      "could not allocate %d bytes (%s)", (int)s, strerror(errno));
 #else
-    Error(SYSTEM_ERROR, TermNil, "could not allocate %d bytes", (int)s);
+    snprintf(ErrorMessage, MAX_ERROR_MSG_SIZE,
+	      "could not allocate %d bytes", (int)s);
 #endif
+    PrologMode = OldPrologMode;
     return FALSE;
   }
   if (a != WorkSpaceTop) {
-    Error(SYSTEM_ERROR, TermNil, "mmap could not grow memory at %p, got %p", WorkSpaceTop, a );
+    ErrorMessage = ErrorSay;
+    snprintf(ErrorMessage, MAX_ERROR_MSG_SIZE,
+	      "mmap could not grow memory at %p, got %p", WorkSpaceTop, a );
+    PrologMode = OldPrologMode;
     return FALSE;
   }
   
   WorkSpaceTop = (char *) a + s;
+  PrologMode = OldPrologMode;
   return TRUE;
 #endif /* YAPOR */
 }
@@ -688,21 +755,33 @@ ExtendWorkSpace(Int s)
 {
   MALLOC_T ptr;
   int shm_id;
+  prolog_exec_mode OldPrologMode = PrologMode;
 
+  PrologMode = ExtendStackMode;
   /* mapping heap area */
   if((shm_id = shmget(IPC_PRIVATE, (size_t)s, SHM_R|SHM_W)) == -1) {
-    Error(SYSTEM_ERROR, TermNil, "could not shmget %d bytes", s);
+    ErrorMessage = ErrorSay;
+    snprintf(ErrorMessage, MAX_ERROR_MSG_SIZE,
+	      "could not shmget %d bytes", s);
+    PrologMode = OldPrologMode;
     return(FALSE);
    }
   if((ptr = (MALLOC_T)shmat(shm_id, WorkSpaceTop, 0)) == (MALLOC_T) -1) {
-    Error(SYSTEM_ERROR, TermNil, "could not shmat at %p", MMAP_ADDR);
+    ErrorMessage = ErrorSay;
+    snprintf(ErrorMessage, MAX_ERROR_MSG_SIZE,
+	      "could not shmat at %p", MMAP_ADDR);
+    PrologMode = OldPrologMode;
     return(FALSE);
   }
   if (shmctl(shm_id, IPC_RMID, 0) != 0) {
-    Error(SYSTEM_ERROR, TermNil, "could not remove shm segment", shm_id);
+    ErrorMessage = ErrorSay;
+    snprintf(ErrorMessage, MAX_ERROR_MSG_SIZE,
+	      "could not remove shm segment", shm_id);
+    PrologMode = OldPrologMode;
     return(FALSE);
   }
   WorkSpaceTop = (char *) ptr + s;
+  PrologMode = OldPrologMode;
   return(TRUE);
 }
 
@@ -751,10 +830,17 @@ int
 ExtendWorkSpace(Int s)
 {
   MALLOC_T ptr = (MALLOC_T)sbrk(s);
+  prolog_exec_mode OldPrologMode = PrologMode;
+
+  PrologMode = ExtendStackMode;
   if (ptr == ((MALLOC_T) - 1)) {
-     Error(SYSTEM_ERROR, TermNil, "could not expand stacks over %d bytes", s);
-     return(FALSE);
+    ErrorMessage = ErrorSay;
+    snprintf(ErrorMessage, MAX_ERROR_MSG_SIZE,
+	      , "could not expand stacks over %d bytes", s);
+    PrologMode = OldPrologMode;
+    return(FALSE);
   }
+  PrologMode = OldPrologMode;
   return TRUE;
 }
 
@@ -874,22 +960,34 @@ int
 ExtendWorkSpace(Int s)
 {
   MALLOC_T ptr;
-  total_space += s;
+  prolog_exec_mode OldPrologMode = PrologMode;
 
+  PrologMode = ExtendStackMode;
+  total_space += s;
   if (total_space < MAX_SPACE) return(TRUE);
   ptr = (MALLOC_T)realloc((void *)HeapBase, total_space);
   if (ptr == NULL) {
-     Error(SYSTEM_ERROR, TermNil, "could not expand stacks %d bytes", s);
-     return(FALSE);
+    ErrorMessage = ErrorSay;
+    snprintf(ErrorMessage, MAX_ERROR_MSG_SIZE,
+	      "could not allocate %d bytes", s);
+    PrologMode = OldPrologMode;
+    return(FALSE);
   }
   if (ptr != (MALLOC_T)HeapBase) {
-     Error(SYSTEM_ERROR, TermNil, "could not expand contiguous stacks  %d bytes", s);
-     return(FALSE);
+    ErrorMessage = ErrorSay;
+    snprintf(ErrorMessage, MAX_ERROR_MSG_SIZE,
+	      "could not expand contiguous stacks  %d bytes", s);
+    PrologMode = OldPrologMode;
+    return(FALSE);
   }
   if ((CELL)ptr & MBIT) {
-     Error(SYSTEM_ERROR, TermNil, "memory at %p conflicts with MBIT %lx", ptr, MBIT);
-     return(FALSE);
+    ErrorMessage = ErrorSay;
+    snprintf(ErrorMessage, MAX_ERROR_MSG_SIZE,
+	      "memory at %p conflicts with MBIT %lx", ptr, MBIT);
+    PrologMode = OldPrologMode;
+    return(FALSE);
   }
+  PrologMode = OldPrologMode;
   return TRUE;
 }
 
diff --git a/C/amasm.c b/C/amasm.c
index 49689cf4d..2bbf5f4e0 100644
--- a/C/amasm.c
+++ b/C/amasm.c
@@ -2606,7 +2606,10 @@ assemble(int mode)
   size = (CELL)code_p;
 #endif
   while ((code_addr = (CODEADDR) AllocCodeSpace(size)) == NULL) {
-    growheap(TRUE);
+    if (!growheap(TRUE)) {
+      Error_TYPE = SYSTEM_ERROR;
+      return (NIL);
+    }
   }
   do_pass();
   YAPLeaveCriticalSection();
diff --git a/C/arrays.c b/C/arrays.c
index 06e62ecb5..814077624 100644
--- a/C/arrays.c
+++ b/C/arrays.c
@@ -442,7 +442,7 @@ AllocateStaticArraySpace(StaticArrayEntry *p, static_array_types atype, Int arra
   while ((p->ValueOfVE.floats = (Float *) AllocAtomSpace(asize) ) == NULL) {
     YAPLeaveCriticalSection();
     if (!growheap(FALSE)) {
-      Error(SYSTEM_ERROR, TermNil, "YAP failed to reserve space in growheap");
+      Error(SYSTEM_ERROR, TermNil, ErrorMessage);
       return;
     }
     YAPEnterCriticalSection();
@@ -636,11 +636,14 @@ p_create_array(void)
     farray = MkFunctor(AtomArray, size);
     if (H+1+size > ASP-1024) {
       if (!gc(2, ENV, P)) {
-	Error(SYSTEM_ERROR,TermNil,"YAP could not grow stack in array/2");
+	Error(OUT_OF_STACK_ERROR,TermNil,ErrorMessage);
 	return(FALSE);
       } else {
 	if (H+1+size > ASP-1024) {
-	  growstack( sizeof(CELL) * (size+1-(H-ASP-1024)));
+	  if (!growstack( sizeof(CELL) * (size+1-(H-ASP-1024)))) {
+	    Error(SYSTEM_ERROR, TermNil, ErrorMessage);
+	    return FALSE;
+	  }
 	}
       }
       goto restart;
@@ -666,7 +669,7 @@ p_create_array(void)
       if (H+1+size > ASP-1024) {
 	WRITE_UNLOCK(ae->ARWLock);
 	if (!gc(2, ENV, P)) {
-	  Error(SYSTEM_ERROR,TermNil,"YAP could not grow stack in array/2");
+	  Error(OUT_OF_STACK_ERROR,TermNil,ErrorMessage);
 	  return(FALSE);
 	} else
 	  goto restart;
@@ -684,7 +687,7 @@ p_create_array(void)
       else {
 	if (H+1+size > ASP-1024) {
 	  if (!gc(2, ENV, P)) {
-	    Error(SYSTEM_ERROR,TermNil,"YAP could not grow stack in array/2");
+	    Error(OUT_OF_STACK_ERROR,TermNil,ErrorMessage);
 	    return(FALSE);
 	  } else
 	    goto restart;
diff --git a/C/attvar.c b/C/attvar.c
index c8affbaa3..7c7993e89 100644
--- a/C/attvar.c
+++ b/C/attvar.c
@@ -353,7 +353,10 @@ BuildNewAttVar(Term t, Int i, Term tatt)
     H[0] = t;
     H[1] = tatt;
     H += 2;
-    growglobal(NULL);
+    if (!growglobal(NULL)) {
+      Error(SYSTEM_ERROR, t, ErrorMessage);
+      return FALSE;
+    }
     H -= 2;
     t = H[0];
     tatt = H[1];
diff --git a/C/c_interface.c b/C/c_interface.c
index 017fb42d7..6a151d683 100644
--- a/C/c_interface.c
+++ b/C/c_interface.c
@@ -602,7 +602,7 @@ YAP_AllocSpaceFromYap(unsigned int size)
 
   if ((ptr = AllocCodeSpace(size)) == NULL) {
     if (!growheap(FALSE)) {
-      Error(SYSTEM_ERROR, TermNil, "YAP failed to reserve space in growheap");
+      Error(SYSTEM_ERROR, TermNil, ErrorMessage);
       return(NULL);
     }
   }
diff --git a/C/cdmgr.c b/C/cdmgr.c
index c3a556d15..f24d04e95 100644
--- a/C/cdmgr.c
+++ b/C/cdmgr.c
@@ -87,8 +87,6 @@ STATIC_PROTO(void  list_all_predicates_in_use, (void));
 
 static int      compile_mode = 1;
 
-static char     ErrorSay[256];
-
 /******************************************************************
   
 			EXECUTING PROLOG CLAUSES
@@ -733,7 +731,7 @@ static void  expand_consult(void)
   /* I assume it always works ;-) */
   while ((new_cl = (consult_obj *)AllocCodeSpace(sizeof(consult_obj)*ConsultCapacity)) == NULL) {
     if (!growheap(FALSE)) {
-      Error(SYSTEM_ERROR,TermNil,"Could not expand consult space: Heap crashed against Stacks");
+      Error(SYSTEM_ERROR,TermNil,ErrorMessage);
       return;
     }
   }
diff --git a/C/compiler.c b/C/compiler.c
index 7c0253514..51052dc04 100644
--- a/C/compiler.c
+++ b/C/compiler.c
@@ -141,8 +141,6 @@ jmp_buf CompilerBotch;
 
 #define IsNewVar(v) (Addr(v)<freep0 || Addr(v)>freep)
 
-static char ErrorSay[80];
-
 inline static void pop_code(void);
 
 inline static void
@@ -2768,15 +2766,13 @@ cclause(Term inp_clause, int NOfArgs, int mod)
       Int osize = 2*sizeof(CELL)*(ASP-H);
       ARG1 = my_clause;
       if (!gc(2, ENV, P)) {
-	Error_TYPE = SYSTEM_ERROR;
+	Error_TYPE = OUT_OF_STACK_ERROR;
 	Error_Term = my_clause;
-	ErrorMessage = "not enough stack";
       }
       if (osize > ASP-H) {
 	if (!growstack(2*sizeof(CELL)*(ASP-H))) {
 	  Error_TYPE = SYSTEM_ERROR;
 	  Error_Term = my_clause;
-	  ErrorMessage = "not enough stack";
 	}
       }
       my_clause = ARG1;
@@ -2796,7 +2792,6 @@ cclause(Term inp_clause, int NOfArgs, int mod)
     reset_vars();
     Error_TYPE = SYSTEM_ERROR;
     Error_Term = TermNil;
-    ErrorMessage = "not enough heap space to compile clause";
     return(0);
   }
  restart_compilation:
diff --git a/C/corout.c b/C/corout.c
index fcd1368ad..37f72221c 100644
--- a/C/corout.c
+++ b/C/corout.c
@@ -564,7 +564,10 @@ freeze_goal(Term t, Term g)
     if (H0 - (CELL *)vs < 1024) {
       ARG1 = t;
       ARG2 = g;
-      growglobal(NULL);
+      if (!growglobal(NULL)) {
+	Error(SYSTEM_ERROR, t, ErrorMessage);
+	return FALSE;
+      }
       t = ARG1;
       g = ARG2;
     }
diff --git a/C/dbase.c b/C/dbase.c
index 99b2d6443..ef05613da 100644
--- a/C/dbase.c
+++ b/C/dbase.c
@@ -1657,7 +1657,7 @@ p_rcda(void)
     return (unify(ARG3, TRef));
   case SOVF_ERROR_IN_DB:
     if (!gc(3, ENV, P)) {
-      Error(SYSTEM_ERROR, TermNil, "YAP could not grow stack in recorda/3");
+      Error(OUT_OF_STACK_ERROR, TermNil, ErrorMessage);
       return(FALSE);
     }
     goto recover_record;
@@ -1666,7 +1666,7 @@ p_rcda(void)
     return(FALSE);
   case OVF_ERROR_IN_DB:
     if (!growheap(FALSE)) {
-      Error(SYSTEM_ERROR, TermNil, "YAP could not grow heap in recorda/3");
+      Error(SYSTEM_ERROR, TermNil, ErrorMessage);
       return(FALSE);
     } else
       goto recover_record;
@@ -1696,7 +1696,7 @@ p_rcdap(void)
     return (unify(ARG3, TRef));
   case SOVF_ERROR_IN_DB:
     if (!gc(3, ENV, P)) {
-      Error(SYSTEM_ERROR, TermNil, "YAP could not grow stack in recorda/3");
+      Error(OUT_OF_STACK_ERROR, TermNil, ErrorMessage);
       return(FALSE);
     }
     goto recover_record;
@@ -1705,7 +1705,7 @@ p_rcdap(void)
     return(FALSE);
   case OVF_ERROR_IN_DB:
     if (!growheap(FALSE)) {
-      Error(SYSTEM_ERROR, TermNil, "YAP could not grow heap in recorda/3");
+      Error(SYSTEM_ERROR, TermNil, ErrorMessage);
       return(FALSE);
     } else
       goto recover_record;
@@ -1735,7 +1735,7 @@ p_rcdz(void)
     return (unify(ARG3, TRef));
   case SOVF_ERROR_IN_DB:
     if (!gc(3, ENV, P)) {
-      Error(SYSTEM_ERROR, TermNil, "YAP could not grow stack in recordz/3");
+      Error(OUT_OF_STACK_ERROR, TermNil, ErrorMessage);
       return(FALSE);
     }
     goto recover_record;
@@ -1744,7 +1744,7 @@ p_rcdz(void)
     return(FALSE);
   case OVF_ERROR_IN_DB:
     if (!growheap(FALSE)) {
-      Error(SYSTEM_ERROR, TermNil, "YAP could not grow heap in recordz/3");
+      Error(SYSTEM_ERROR, TermNil, ErrorMessage);
       return(FALSE);
     } else
       goto recover_record;
@@ -1774,7 +1774,7 @@ p_rcdzp(void)
     return (unify(ARG3, TRef));
   case SOVF_ERROR_IN_DB:
     if (!gc(3, ENV, P)) {
-      Error(SYSTEM_ERROR, TermNil, "YAP could not grow stack in recordz/3");
+      Error(OUT_OF_STACK_ERROR, TermNil, ErrorMessage);
       return(FALSE);
     }
     goto recover_record;
@@ -1783,7 +1783,7 @@ p_rcdzp(void)
     return(FALSE);
   case OVF_ERROR_IN_DB:
     if (!growheap(FALSE)) {
-      Error(SYSTEM_ERROR, TermNil, "YAP could not grow heap in recordz/3");
+      Error(SYSTEM_ERROR, TermNil, ErrorMessage);
       return(FALSE);
     } else
       goto recover_record;
@@ -1821,7 +1821,7 @@ p_rcdstatp(void)
     return (unify(ARG4,TRef));
   case SOVF_ERROR_IN_DB:
     if (!gc(3, ENV, P)) {
-      Error(SYSTEM_ERROR, TermNil, "YAP could not grow stack in record_stat_source/3");
+      Error(OUT_OF_STACK_ERROR, TermNil, ErrorMessage);
       return(FALSE);
     }
     goto recover_record;
@@ -1830,7 +1830,7 @@ p_rcdstatp(void)
     return(FALSE);
   case OVF_ERROR_IN_DB:
     if (!growheap(FALSE)) {
-      Error(SYSTEM_ERROR, TermNil, "YAP could not grow heap in record_stat_source/3");
+      Error(SYSTEM_ERROR, TermNil, ErrorMessage);
       return(FALSE);
     } else
       goto recover_record;
@@ -1863,7 +1863,7 @@ p_drcdap(void)
     return (unify(ARG3, TRef));
   case SOVF_ERROR_IN_DB:
     if (!gc(4, ENV, P)) {
-      Error(SYSTEM_ERROR, TermNil, "YAP could not grow stack in recorda/3");
+      Error(OUT_OF_STACK_ERROR, TermNil, ErrorMessage);
       return(FALSE);
     }
     goto recover_record;
@@ -1872,7 +1872,7 @@ p_drcdap(void)
     return(FALSE);
   case OVF_ERROR_IN_DB:
     if (!growheap(FALSE)) {
-      Error(SYSTEM_ERROR, TermNil, "YAP could not grow heap in recorda/3");
+      Error(SYSTEM_ERROR, TermNil, ErrorMessage);
       return(FALSE);
     } else
       goto recover_record;
@@ -1906,7 +1906,7 @@ p_drcdzp(void)
     return (unify(ARG3, TRef));
   case SOVF_ERROR_IN_DB:
     if (!gc(4, ENV, P)) {
-      Error(SYSTEM_ERROR, TermNil, "YAP could not grow stack in recordz/3");
+      Error(OUT_OF_STACK_ERROR, TermNil, ErrorMessage);
       return(FALSE);
     }
     goto recover_record;
@@ -1915,7 +1915,7 @@ p_drcdzp(void)
     return(FALSE);
   case OVF_ERROR_IN_DB:
     if (!growheap(FALSE)) {
-      Error(SYSTEM_ERROR, TermNil, "YAP could not grow heap in recordz/3");
+      Error(SYSTEM_ERROR, TermNil, ErrorMessage);
       return(FALSE);
     } else
       goto recover_record;
@@ -1951,7 +1951,7 @@ p_rcdaifnot(void)
     return (unify(ARG3, TRef));
   case SOVF_ERROR_IN_DB:
     if (!gc(3, ENV, P)) {
-      Error(SYSTEM_ERROR, TermNil, "YAP could not grow stack in recordaifnot/3");
+      Error(OUT_OF_STACK_ERROR, TermNil, ErrorMessage);
       return(FALSE);
     }
     goto recover_record;
@@ -1960,7 +1960,7 @@ p_rcdaifnot(void)
     return(FALSE);
   case OVF_ERROR_IN_DB:
     if (!growheap(FALSE)) {
-      Error(SYSTEM_ERROR, TermNil, "YAP could not grow heap in recordzifnot/3");
+      Error(SYSTEM_ERROR, TermNil, ErrorMessage);
       return(FALSE);
     } else
       goto recover_record;
@@ -1993,7 +1993,7 @@ p_rcdzifnot(void)
     return (unify(ARG3, TRef));
   case SOVF_ERROR_IN_DB:
     if (!gc(3, ENV, P)) {
-      Error(SYSTEM_ERROR, TermNil, "YAP could not grow stack in recordaifnot/3");
+      Error(OUT_OF_STACK_ERROR, TermNil, ErrorMessage);
       return(FALSE);
     }
     goto recover_record;
@@ -2002,7 +2002,7 @@ p_rcdzifnot(void)
     return(FALSE);
   case OVF_ERROR_IN_DB:
     if (!growheap(FALSE)) {
-      Error(SYSTEM_ERROR, TermNil, "YAP could not grow heap in recordzifnot/3");
+      Error(SYSTEM_ERROR, TermNil, ErrorMessage);
       return(FALSE);
     } else
       goto recover_record;
@@ -2330,7 +2330,7 @@ i_log_upd_recorded(LogUpdDBProp AtProp)
     if (AtProp->Index == NULL) {
       if((AtProp->Index = new_lu_index(AtProp)) == NULL) {
 	if (!growheap(FALSE)) {
-	  Error(SYSTEM_ERROR, TermNil, "YAP failed to reserve space in growheap");
+	  Error(SYSTEM_ERROR, TermNil, ErrorMessage);
 	  cut_fail();
 	}
 	twork = Deref(ARG2);
@@ -2361,7 +2361,10 @@ i_log_upd_recorded(LogUpdDBProp AtProp)
       /* make sure the garbage collector sees what we want it to see! */
       EXTRA_CBACK_ARG(3,1) = AbsAppl((CELL *)ep);
       /* oops, we are in trouble, not enough stack space */
-      gc(3, ENV, CP);
+      if (!gc(3, ENV, CP)) {
+	Error(OUT_OF_STACK_ERROR, TermNil, ErrorMessage);
+	return(FALSE);
+      }
       PreviousHeap = H;
       twork = Deref(ARG2);
     }
@@ -2405,7 +2408,10 @@ i_log_upd_recorded(LogUpdDBProp AtProp)
 	/* make sure the garbage collector sees what we want it to see! */
 	EXTRA_CBACK_ARG(3,1) = AbsAppl((CELL *)ep);
 	/* oops, we are in trouble, not enough stack space */
-	gc(3, ENV, CP);
+	if(!gc(3, ENV, CP)) {
+	  Error(OUT_OF_STACK_ERROR, TermNil, ErrorMessage);
+	  return(FALSE);
+	}
 	PreviousHeap = H;
       }
       if (unify(ARG2, TermDB))
@@ -2555,7 +2561,10 @@ i_recorded(DBProp AtProp)
       /* make sure the garbage collector sees what we want it to see! */
       EXTRA_CBACK_ARG(3,1) = (CELL)ref;
       /* oops, we are in trouble, not enough stack space */
-      gc(3, ENV, CP);
+      if (!gc(3, ENV, CP)) {
+	Error(OUT_OF_STACK_ERROR, TermNil, ErrorMessage);
+	return(FALSE);
+      }
       twork = Deref(ARG2);
       t3 = Deref(ARG3);
     }
@@ -2614,7 +2623,10 @@ i_recorded(DBProp AtProp)
 	EXTRA_CBACK_ARG(3,2) = MkIntegerTerm(((Int)mask));
 	EXTRA_CBACK_ARG(3,3) = MkIntegerTerm(((Int)key));
 	/* oops, we are in trouble, not enough stack space */
-	gc(3, ENV, CP);
+	if (!gc(3, ENV, CP)) {
+	  Error(OUT_OF_STACK_ERROR, TermNil, ErrorMessage);
+	  return(FALSE);
+	}
 	READ_LOCK(AtProp->DBRWLock);
       }
     } while (TRUE);
@@ -2676,7 +2688,10 @@ c_log_upd_recorded(DBRef *ep, int flags)
       /* make sure the garbage collector sees what we want it to see! */
       EXTRA_CBACK_ARG(3,1) = AbsAppl((CELL *)ep);
       /* oops, we are in trouble, not enough stack space */
-      gc(3, ENV, CP);
+      if (!gc(3, ENV, CP)) {
+	Error(OUT_OF_STACK_ERROR, TermNil, ErrorMessage);
+	return(FALSE);
+      }
       PreviousHeap = H;
     }
     unify(ARG2, TermDB);
@@ -2704,7 +2719,10 @@ c_log_upd_recorded(DBRef *ep, int flags)
 	/* make sure the garbage collector sees what we want it to see! */
 	EXTRA_CBACK_ARG(3,1) = AbsAppl((CELL *)ep);
 	/* oops, we are in trouble, not enough stack space */
-	gc(3, ENV, CP);
+	if (!gc(3, ENV, CP)) {
+	  Error(OUT_OF_STACK_ERROR, TermNil, ErrorMessage);
+	  return(FALSE);
+	}
 	PreviousHeap = H;
       }
       if (unify(ARG2, TermDB))
@@ -2815,7 +2833,10 @@ c_recorded(int flags)
       /* make sure the garbage collector sees what we want it to see! */
       EXTRA_CBACK_ARG(3,1) = (CELL)ref;
       /* oops, we are in trouble, not enough stack space */
-      gc(3, ENV, CP);
+      if (!gc(3, ENV, CP)) {
+	Error(OUT_OF_STACK_ERROR, TermNil, ErrorMessage);
+	return(FALSE);
+      }
       PreviousHeap = H;
     }
     unify(ARG2, TermDB);
@@ -2845,7 +2866,10 @@ c_recorded(int flags)
 	/* make sure the garbage collector sees what we want it to see! */
 	EXTRA_CBACK_ARG(3,1) = (CELL)ref;
 	/* oops, we are in trouble, not enough stack space */
-	gc(3, ENV, CP);
+	if (!gc(3, ENV, CP)) {
+	  Error(OUT_OF_STACK_ERROR, TermNil, ErrorMessage);
+	  return(FALSE);
+	}
 	PreviousHeap = H;
       }
       if (unify(ARG2, TermDB))
@@ -3005,7 +3029,10 @@ p_first_instance(void)
 #endif
   while ((TermDB = GetDBTerm(ref)) == (CELL)0) {
     /* oops, we are in trouble, not enough stack space */
-    gc(3, ENV, P);
+    if (!gc(3, ENV, P)) {
+      Error(OUT_OF_STACK_ERROR, TermNil, ErrorMessage);
+      return(FALSE);
+    }
   }
   if (IsVarTerm(TermDB)) {
     unify(TermDB, ARG2);
@@ -3701,7 +3728,10 @@ p_instance(void)
   }
   while ((TermDB = GetDBTerm(dbr)) == (CELL)0) {
     /* oops, we are in trouble, not enough stack space */
-    gc(2, ENV, P);
+    if (!gc(2, ENV, P)) {
+      Error(OUT_OF_STACK_ERROR, TermNil, ErrorMessage);
+      return(FALSE);
+    }
     t1 = Deref(ARG1);
   }
   return (unify(ARG2, TermDB));
@@ -3889,7 +3919,10 @@ FetchTermFromDB(DBRef ref, int args)
   Term TDB;
   while ((TDB = GetDBTerm(ref)) == (CELL)0) {
     /* oops, we are in trouble, not enough stack space */
-    gc(args, ENV, P);
+    if (!gc(args, ENV, P)) {
+      Error(OUT_OF_STACK_ERROR, TermNil, ErrorMessage);
+      return(TermNil);
+    }
   }
   return(TDB);
 }
@@ -3916,7 +3949,7 @@ StoreTermInDB(int arg, int nargs)
       break;
     case SOVF_ERROR_IN_DB:
       if (!gc(nargs, ENV, P)) {
-	Error(SYSTEM_ERROR, TermNil, "YAP could not grow stack in enqueue/2");
+	Error(OUT_OF_STACK_ERROR, TermNil, ErrorMessage);
 	return(FALSE);
       } else {
 	t = Deref(XREGS[arg]);
@@ -3927,7 +3960,7 @@ StoreTermInDB(int arg, int nargs)
       return(FALSE);
     case OVF_ERROR_IN_DB:
       if (!growheap(FALSE)) {
-	Error(SYSTEM_ERROR, TermNil, "YAP could not grow heap in enqueue/2");
+	Error(SYSTEM_ERROR, TermNil, ErrorMessage);
 	return(FALSE);
       } else {
 	t = Deref(XREGS[arg]);
@@ -3953,7 +3986,7 @@ p_init_queue(void)
   } else {
     while ((dbq = (db_queue *)AllocDBSpace(sizeof(db_queue))) == NULL) {
       if (!growheap(FALSE)) {
-	Error(SYSTEM_ERROR, TermNil, "YAP failed to reserve space in growheap");
+	Error(SYSTEM_ERROR, TermNil, ErrorMessage);
 	return(FALSE);
       }
     }
diff --git a/C/errors.c b/C/errors.c
index a116cc93c..c1cd83481 100644
--- a/C/errors.c
+++ b/C/errors.c
@@ -300,8 +300,7 @@ cl_position(yamop *ptr)
   fprintf(stderr,"  %s\n", tp);
 }
 
-static void
-error_exit_yap (int value)
+static void dump_stack()
 {
   choiceptr b_ptr = B;
   CELL *env_ptr = ENV;
@@ -324,6 +323,13 @@ error_exit_yap (int value)
     }
     fprintf(stderr," ]\n");
   }
+}
+
+
+static void
+error_exit_yap (int value)
+{
+  dump_stack();
   exit_yap(value);
 }
 
@@ -898,6 +904,45 @@ Error (yap_error_number type, Term where, char *format,...)
       serious = TRUE;
     }
     break;
+  case OUT_OF_HEAP_ERROR:
+    {
+      int i;
+
+      dump_stack();
+      i = strlen(tmpbuf);
+      nt[0] = MkAtomTerm(LookupAtom("out_of_stack_error"));
+      tp = tmpbuf+i;
+      psize -= i;
+      fun = MkFunctor(LookupAtom("error"),2);
+      serious = TRUE;
+    }
+    break;
+  case OUT_OF_STACK_ERROR:
+    {
+      int i;
+
+      dump_stack();
+      i = strlen(tmpbuf);
+      nt[0] = MkAtomTerm(LookupAtom("out_of_stack_error"));
+      tp = tmpbuf+i;
+      psize -= i;
+      fun = MkFunctor(LookupAtom("error"),2);
+      serious = TRUE;
+    }
+    break;
+  case OUT_OF_TRAIL_ERROR:
+    {
+      int i;
+
+      dump_stack();
+      i = strlen(tmpbuf);
+      nt[0] = MkAtomTerm(LookupAtom("out_of_trail_error"));
+      tp = tmpbuf+i;
+      psize -= i;
+      fun = MkFunctor(LookupAtom("error"),2);
+      serious = TRUE;
+    }
+    break;
   case PERMISSION_ERROR_ACCESS_PRIVATE_PROCEDURE:
     {
       int i;
@@ -1505,7 +1550,15 @@ Error (yap_error_number type, Term where, char *format,...)
     /* This is used by some complex procedures to detect there was an error */
     ErrorMessage = RepAtom(AtomOfTerm(nt[0]))->StrOfAE;
   }
-  nt[1] = MkPairTerm(MkAtomTerm(LookupAtom(tmpbuf)), all_calls());
+  switch (type) {
+  case OUT_OF_HEAP_ERROR:
+  case OUT_OF_STACK_ERROR:
+  case OUT_OF_TRAIL_ERROR:
+    nt[1] = MkAtomTerm(LookupAtom(tmpbuf));
+    break;
+  default:
+    nt[1] = MkPairTerm(MkAtomTerm(LookupAtom(tmpbuf)), all_calls());
+  }
   if (serious) {
     if (type == PURE_ABORT)
       JumpToEnv(MkAtomTerm(LookupAtom("abort")));
diff --git a/C/grow.c b/C/grow.c
index d4a621e43..e7f84f547 100644
--- a/C/grow.c
+++ b/C/grow.c
@@ -26,6 +26,10 @@
 #include <string.h>
 #endif
 
+#if !HAVE_STRNCAT
+#define strncat(s0,s1,sz)   strcat(s0,s1)
+#endif
+
 static int heap_overflows = 0;
 static Int total_heap_overflow_time = 0;
 
@@ -476,7 +480,9 @@ local_growheap(long size, int fix_code)
 
   /* adjust to a multiple of 256) */
   size = AdjustPageSize(size);
+  ErrorMessage = NULL;
   if (!ExtendWorkSpace(size)) {
+    strncat(ErrorMessage,": heap crashed against stacks", MAX_ERROR_MSG_SIZE);
     return(FALSE);
   }
   start_growth_time = cputime();
@@ -522,7 +528,9 @@ local_growglobal(long size, CELL **ptr)
 
   /* adjust to a multiple of 256) */
   size = AdjustPageSize(size);
+  ErrorMessage = NULL;
   if (!ExtendWorkSpace(size)) {
+    strncat(ErrorMessage,": global crashed against local", MAX_ERROR_MSG_SIZE);
     return(FALSE);
   }
   start_growth_time = cputime();
@@ -654,7 +662,11 @@ growheap(int fix_code)
 #ifdef TABLING
   fix_tabling_info();
 #endif
-  return(sz >= sizeof(CELL) * 16 * 1024L);
+  if (sz >= sizeof(CELL) * 16 * 1024L) {
+    return (TRUE);
+  }
+  /* failed */
+  return(FALSE);
 }
 
 int
@@ -686,7 +698,9 @@ growstack(long size)
 #endif
   /* adjust to a multiple of 256) */
   size = AdjustPageSize(size);
+  ErrorMessage = NULL;
   if (!ExtendWorkSpace(size)) {
+    strncat(ErrorMessage,": local crashed against global", MAX_ERROR_MSG_SIZE);
     return(FALSE);
   }
   start_growth_time = cputime();
@@ -803,7 +817,9 @@ growstack_in_parser(tr_fr_ptr *old_trp, TokEntry **tksp, VarEntry **vep)
 #endif
   /* adjust to a multiple of 256) */
   size = AdjustPageSize(size);
+  ErrorMessage = NULL;
   if (!ExtendWorkSpace(size)) {
+    strncat(ErrorMessage,": parser stack overflowed", MAX_ERROR_MSG_SIZE);
     return(FALSE);
   }
   start_growth_time = cputime();
@@ -861,7 +877,9 @@ growtrail(long size)
     YP_fprintf(YP_stderr, "[TO] Trail overflow %d\n", trail_overflows);
     YP_fprintf(YP_stderr, "[TO]    growing the trail %ld bytes\n", size);
   }
+  ErrorMessage = NULL;
   if (!ExtendWorkSpace(size)) {
+    strncat(ErrorMessage,": trail stack overflowed", MAX_ERROR_MSG_SIZE);
     return(FALSE);
   }
   YAPEnterCriticalSection();
diff --git a/C/heapgc.c b/C/heapgc.c
index 7a64a5b88..da3380298 100644
--- a/C/heapgc.c
+++ b/C/heapgc.c
@@ -742,6 +742,9 @@ vsc_stop(void) {
   return(1);
 }
 
+#endif
+
+#ifdef CHECK_GLOBAL
 static void
 check_global(void) {
   CELL *current;
@@ -814,8 +817,9 @@ check_global(void) {
   vars[gc_susp] = 0;
 #endif
 }
-#endif
-
+#else
+#define check_global()
+#endif /* CHECK_GLOBAL */
 
 /* mark a heap object and all heap objects accessible from it */
 
@@ -2975,7 +2979,10 @@ do_gc(Int predarity, CELL *current_env, yamop *nextop)
 
 #if COROUTINING
   if (H0 - (CELL *)ReadTimedVar(DelayedVars) < 1024+(2*NUM_OF_ATTS)) {
-    growglobal(&current_env);
+    if (!growglobal(&current_env)) {
+      Error(SYSTEM_ERROR, TermNil, ErrorMessage);
+      return FALSE;
+    }
   }
 #endif
 #ifdef INSTRUMENT_GC
@@ -3028,7 +3035,7 @@ do_gc(Int predarity, CELL *current_env, yamop *nextop)
   if (HeapTop >= GlobalBase - MinHeapGap) {
     *--ASP = (CELL)current_env;
     if (!growheap(FALSE)) {
-      Error(SYSTEM_ERROR, TermNil, "YAP could not grow heap before garbage collection");
+      Error(SYSTEM_ERROR, TermNil, ErrorMessage);
       return(FALSE);
     }
     current_env = (CELL *)*ASP;
@@ -3086,9 +3093,7 @@ do_gc(Int predarity, CELL *current_env, yamop *nextop)
     YP_fprintf(YP_stderr, "[GC]   Left %ld cells free in stacks.\n",
 	       (unsigned long int)(ASP-H));
   }
-#ifdef DEBUG
   check_global();
-#endif
   return(effectiveness);
 }
 
@@ -3171,9 +3176,7 @@ gc(Int predarity, CELL *current_env, yamop *nextop)
       gc_margin = gap;
     while (gc_margin >= gap && !growstack(gc_margin))
       gc_margin = gc_margin/2;
-#ifdef DEBUG
     check_global();
-#endif
     return(gc_margin >= gap);
   }
   /*
diff --git a/C/index.c b/C/index.c
index 356051677..def401d63 100644
--- a/C/index.c
+++ b/C/index.c
@@ -1415,7 +1415,7 @@ PredIsIndexable(PredEntry *ap)
 #endif
     if ((indx_out = assemble(ASSEMBLING_INDEX)) == NIL) {
       if (!growheap(FALSE)) {
-	Error(SYSTEM_ERROR, TermNil, "YAP failed to reserve space in growheap");
+	Error(SYSTEM_ERROR, TermNil, ErrorMessage);
 	return(FALSE);
       }
       goto restart_index;
diff --git a/C/init.c b/C/init.c
index 75ef522c4..d2df51131 100644
--- a/C/init.c
+++ b/C/init.c
@@ -112,6 +112,9 @@ int             optimizer_on = TRUE;
 
 int             compile_mode = 0;
 
+/******************* storing error messages ****************************/
+char      ErrorSay[MAX_ERROR_MSG_SIZE];
+
 /******************* intermediate buffers **********************/
 
 char FileNameBuf[YAP_FILENAME_MAX], FileNameBuf2[YAP_FILENAME_MAX];
diff --git a/C/iopreds.c b/C/iopreds.c
index 3a9dde254..a6b995dde 100644
--- a/C/iopreds.c
+++ b/C/iopreds.c
@@ -1901,7 +1901,7 @@ p_open_mem_read_stream (void)   /* $open_mem_read_stream(+List,-Stream) */
   }
   while ((nbuf = (char *)AllocAtomSpace((sl+1)*sizeof(char))) == NULL) {
     if (!growheap(FALSE)) {
-      Error(SYSTEM_ERROR, TermNil, "YAP could not grow heap in open_mem_read_stream");
+      Error(SYSTEM_ERROR, TermNil, ErrorMessage);
       return(FALSE);
     }
   }
@@ -1955,7 +1955,7 @@ p_open_mem_write_stream (void)   /* $open_mem_write_stream(-Stream) */
 
   while ((nbuf = (char *)AllocAtomSpace(page_size*sizeof(char))) == NULL) {
     if (!growheap(FALSE)) {
-      Error(SYSTEM_ERROR, TermNil, "YAP could not grow heap in open_mem_write_stream");
+      Error(SYSTEM_ERROR, TermNil, ErrorMessage);
       return(FALSE);
     }
   }
@@ -2412,7 +2412,7 @@ p_peek_mem_write_stream (void)
     if (H + 1024 >= ASP) {
       H = HI;
       if (!gc(3, ENV, P)) {
-	Error(SYSTEM_ERROR, TermNil, "YAP could not grow stack in peek_mem_write_stream/2");
+	Error(OUT_OF_STACK_ERROR, TermNil, ErrorMessage);
 	return(FALSE);
       }
       i = 0;
@@ -3516,6 +3516,8 @@ static  pads pad_entries[16], *pad_max = pad_entries;
 
 static int
 format_putc(int sno, int ch) {
+  if (format_buf_size == -1)
+    return(EOF);
   if (ch == 10) {
     char *ptr = format_base;
 #if MAC || _MSC_VER
@@ -3537,7 +3539,7 @@ format_putc(int sno, int ch) {
       char *newbuf;
 
       if ((newbuf = AllocAtomSpace(new_max_size*sizeof(char))) == NULL) {
-	FreeAtomSpace(format_base);
+	format_buf_size = -1;
 	Error(SYSTEM_ERROR, TermNil, "YAP could not grow heap for format/2");
 	return(EOF);
       }
@@ -3678,6 +3680,10 @@ format(Term tail, Term args, int sno)
   format_error = FALSE;
   while (!IsVarTerm (head) && IsIntTerm (head))
     {
+      if (format_buf_size == -1) {
+	FreeAtomSpace(format_base);
+	return(FALSE);
+      }
       ch = IntOfTerm (head);
       if (ch == '~')
 	{
@@ -4330,6 +4336,10 @@ format(Term tail, Term args, int sno)
       head = HeadOfTerm (tail);
       tail = TailOfTerm (tail);
     }
+  if (format_buf_size == -1) {
+    FreeAtomSpace(format_base);
+    return(FALSE);
+  }
   for (ptr = format_base; ptr < format_ptr; ptr++) {
     Stream[sno].stream_putc(sno, *ptr);
   }
@@ -4650,7 +4660,7 @@ p_char_conversion(void)
     CharConversionTable2 = AllocCodeSpace(NUMBER_OF_CHARS*sizeof(char));
     while (CharConversionTable2 == NULL) {
       if (!growheap(FALSE)) {
-	Error(SYSTEM_ERROR, TermNil, "YAP could not grow heap in char_conversion/2");
+	Error(SYSTEM_ERROR, TermNil, ErrorMessage);
 	return(FALSE);
       }
     }
diff --git a/C/sort.c b/C/sort.c
index ef8b7bfb3..8e1f4e72a 100644
--- a/C/sort.c
+++ b/C/sort.c
@@ -59,7 +59,7 @@ build_new_list(CELL *pt, Term t)
     pt += 2;
     if (pt > ASP - 4096) {
       if (!gc(2, ENV, P)) {
-	Error(SYSTEM_ERROR, TermNil, "YAP could not grow stack in sort/2");
+	Error(OUT_OF_STACK_ERROR, TermNil, ErrorMessage);
 	return(FALSE);
       }
       t = Deref(ARG1);
diff --git a/C/stdpreds.c b/C/stdpreds.c
index 3378175c9..30e771211 100644
--- a/C/stdpreds.c
+++ b/C/stdpreds.c
@@ -668,7 +668,7 @@ p_atom_concat(void)
     if (cptr+sz >= top-1024) {
       ReleasePreAllocCodeSpace((ADDR)cpt0);
       if (!growheap(FALSE)) {
-	Error(SYSTEM_ERROR, TermNil, "YAP could not grow heap in atom_concat/2 ]\n");
+	Error(SYSTEM_ERROR, TermNil, ErrorMessage);
 	return(FALSE);
       }
       goto restart;
@@ -1179,7 +1179,10 @@ p_univ(void)
       if (H > ASP - 1024) {
 	/* restore space */
 	H = Ar;
-	gc(2, ENV, P);
+	if (!gc(2, ENV, P)) {
+	  Error(OUT_OF_STACK_ERROR, TermNil, ErrorMessage);
+	  return(FALSE);
+	}
 	twork = TailOfTerm(Deref(ARG2));
 	goto build_compound;
       }
@@ -1244,7 +1247,10 @@ p_univ(void)
 #endif
       {
 	if (H+arity*2 > ASP-1024) {
-	  gc(2, ENV, P);
+	  if (!gc(2, ENV, P)) {
+	    Error(OUT_OF_STACK_ERROR, TermNil, ErrorMessage);
+	    return(FALSE);
+	  }
 	  tin = Deref(ARG1);
 	}
 	twork = ArrayToList(RepAppl(tin) + 1, arity);
diff --git a/C/sysbits.c b/C/sysbits.c
index cb61b311c..bd60961e5 100644
--- a/C/sysbits.c
+++ b/C/sysbits.c
@@ -1018,6 +1018,10 @@ SearchForTrailFault(void)
 static RETSIGTYPE
 HandleSIGSEGV(int   sig)
 {
+  if (PrologMode & ExtendStackMode) {
+    fprintf(stderr,  "[ FATAL ERROR: OS memory allocation crashed: bailing out ]~n");
+    exit(1);
+  }
   SearchForTrailFault();
 }
 
@@ -1914,27 +1918,32 @@ static Int p_putenv(void)
 /* set a variable in YAP's environment */
 static Int p_file_age(void)
 {
+  char *file_name = RepAtom(AtomOfTerm(Deref(ARG1)))->StrOfAE;
+  if (strcmp(file_name,"user_input") == 0) {
+    return(unify(ARG2,MkIntTerm(-1)));
+  }
 #if HAVE_LSTAT 
-  struct stat buf;
-  char *file_name = RepAtom(AtomOfTerm(Deref(ARG1)))->StrOfAE;
+ {
+   struct stat buf;
 
-  if (lstat(file_name, &buf) == -1) {
-    /* file does not exist, but was opened? Return -1 */
-    return(unify(ARG2, MkIntTerm(-1)));
-  }
-  return(unify(ARG2, MkIntegerTerm(buf.st_mtime)));
+   if (lstat(file_name, &buf) == -1) {
+     /* file does not exist, but was opened? Return -1 */
+     return(unify(ARG2, MkIntTerm(-1)));
+   }
+   return(unify(ARG2, MkIntegerTerm(buf.st_mtime)));
+ }
 #elif defined(__MINGW32__) || _MSC_VER
-  /* for some weird reason _stat did not work with mingw32 */
-  struct _stat buf;
-  char *file_name = RepAtom(AtomOfTerm(Deref(ARG1)))->StrOfAE;
+  {
+    struct _stat buf;
 
-  if (_stat(file_name, &buf) != 0) {
-    /* return an error number */
-    return(unify(ARG2, MkIntTerm(-1)));
+    if (_stat(file_name, &buf) != 0) {
+      /* return an error number */
+      return(unify(ARG2, MkIntTerm(-1)));
+    }
+    return(unify(ARG2, MkIntegerTerm(buf.st_mtime)));
   }
-  return(unify(ARG2, MkIntegerTerm(buf.st_mtime)));
 #else
-  return(unify(ARG2, MkIntTerm(0)));
+  return(unify(ARG2, MkIntTerm(-1)));
 #endif
 }
 
diff --git a/C/tracer.c b/C/tracer.c
index bdbcee1ec..27895c0df 100644
--- a/C/tracer.c
+++ b/C/tracer.c
@@ -113,14 +113,13 @@ low_level_trace(yap_low_level_port port, PredEntry *pred, CELL *args)
 
   vsc_count++;
   /* if (vsc_count < 24200) return; */
-  /* if (vsc_count == 24340) {
+  /* if (vsc_count == 80) {
      printf("Here I go\n");
-     } 
-  */
+     } */
   /* if (vsc_count > 500000) exit(0); */
   /* if (gc_calls < 1) return;*/
 #if defined(__GNUC__)
-  YP_fprintf(YP_stderr,"%llu, %p ", vsc_count, H);
+  YP_fprintf(YP_stderr,"%llu ", vsc_count);
 #endif
   /* check_trail_consistency(); */
   if (pred == NULL) {
diff --git a/C/unify.c b/C/unify.c
index b58dff02d..0829ce9a2 100644
--- a/C/unify.c
+++ b/C/unify.c
@@ -1616,7 +1616,10 @@ p_functor(void)			/* functor(?,?,?) */
     *pt1++ = d0;
     d0 = AbsAppl(H);
     if (pt1+d1 > ENV - CreepFlag) {
-      gc(3, ENV, P);
+      if (!gc(3, ENV, P)) {
+	Error(OUT_OF_STACK_ERROR, TermNil, ErrorMessage);
+	return(FALSE);
+      }
       goto restart;
     }
     while (d1-- > 0) {
@@ -1650,6 +1653,7 @@ p_functor(void)			/* functor(?,?,?) */
   ENDD(d1);
 
   BEGP(pt1);
+
   deref_body(d0, pt1, func_var_2unk, func_var_2nvar);
   Error(INSTANTIATION_ERROR,(CELL)pt1,"functor/3");
   ENDP(pt1);
diff --git a/C/utilpreds.c b/C/utilpreds.c
index 2bb1b16b6..eb6cb2bf4 100644
--- a/C/utilpreds.c
+++ b/C/utilpreds.c
@@ -309,12 +309,15 @@ CopyTerm(Term inp) {
       if ((res = copy_complex_term(Hi-2, Hi-1, Hi, Hi)) < 0) {
 	ARG1 = t;
 	if (res == -1) { /* handle overflow */
-	  gc(2, ENV, P);
+	  if (!gc(2, ENV, P)) {
+	    Error(OUT_OF_STACK_ERROR, TermNil, ErrorMessage);
+	    return(FALSE);
+	  }
 	  t = Deref(ARG1);
 	  goto restart_attached;
 	} else { /* handle overflow */
 	  if (!growheap(FALSE)) {
-	    Error(SYSTEM_ERROR, TermNil, "YAP failed to reserve space in growheap");
+	    Error(SYSTEM_ERROR, TermNil, ErrorMessage);
 	    return(FALSE);
 	  }
 	  t = Deref(ARG1);
@@ -342,12 +345,15 @@ CopyTerm(Term inp) {
       if ((res = copy_complex_term(ap-1, ap+1, Hi, Hi)) < 0) {
 	ARG1 = t;
 	if (res == -1) { /* handle overflow */
-	  gc(2, ENV, P);
+	  if (!gc(2, ENV, P)) {
+	    Error(OUT_OF_STACK_ERROR, TermNil, ErrorMessage);
+	    return(FALSE);
+	  }
 	  t = Deref(ARG1);
 	  goto restart_list;
 	} else { /* handle overflow */
 	  if (!growheap(FALSE)) {
-	    Error(SYSTEM_ERROR, TermNil, "YAP failed to reserve space in growheap");
+	    Error(SYSTEM_ERROR, TermNil, ErrorMessage);
 	    return(FALSE);
 	  }
 	  t = Deref(ARG1);
@@ -374,12 +380,15 @@ CopyTerm(Term inp) {
       if ((res = copy_complex_term(ap, ap+ArityOfFunctor(f), HB0+1, HB0)) < 0) {
 	ARG1 = t;
 	if (res == -1) {
-	  gc(2, ENV, P);
+	  if (!gc(2, ENV, P)) {
+	    Error(OUT_OF_STACK_ERROR, TermNil, ErrorMessage);
+	    return(FALSE);
+	  }
 	  t = Deref(ARG1);
 	  goto restart_appl;
 	} else { /* handle overflow */
 	  if (!growheap(FALSE)) {
-	    Error(SYSTEM_ERROR, TermNil, "YAP failed to reserve space in growheap");
+	    Error(SYSTEM_ERROR, TermNil, ErrorMessage);
 	    return(FALSE);
 	  }
 	  t = Deref(ARG1);
@@ -604,12 +613,15 @@ CopyTermNoDelays(Term inp) {
     res = copy_complex_term_no_delays(ap-1, ap+1, H-2, H-2);
     if (res) {
       if (res == -1) { /* handle overflow */
-	gc(2, ENV, P);
+	if (!gc(2, ENV, P)) {
+	  Error(OUT_OF_STACK_ERROR, TermNil, ErrorMessage);
+	  return(FALSE);
+	}
 	t = Deref(ARG1);
 	goto restart_list;
       } else { /* handle overflow */
 	if (!growheap(FALSE)) {
-	  Error(SYSTEM_ERROR, TermNil, "YAP failed to reserve space in growheap");
+	  Error(SYSTEM_ERROR, TermNil, ErrorMessage);
 	  return(FALSE);
 	}
 	t = Deref(ARG1);
@@ -633,12 +645,15 @@ CopyTermNoDelays(Term inp) {
     res = copy_complex_term_no_delays(ap, ap+ArityOfFunctor(f), HB0+1, HB0);
     if (res) {
       if (res == -1) {
-	gc(2, ENV, P);
+	if (!gc(2, ENV, P)) {
+	  Error(OUT_OF_STACK_ERROR, TermNil, ErrorMessage);
+	  return(FALSE);
+	}
 	t = Deref(ARG1);
 	goto restart_appl;
       } else { /* handle overflow */
 	if (!growheap(FALSE)) {
-	  Error(SYSTEM_ERROR, TermNil, "YAP failed to reserve space in growheap");
+	  Error(SYSTEM_ERROR, TermNil, ErrorMessage);
 	  return(FALSE);
 	}
 	t = Deref(ARG1);
diff --git a/H/rheap.h b/H/rheap.h
index 001c7b047..c73430ddc 100644
--- a/H/rheap.h
+++ b/H/rheap.h
@@ -1073,7 +1073,7 @@ RestoreClause(Clause *Cl, int mode)
 
 	i = pc->u.s.s;
 	startcode = oldcode = (CELL *)NEXTOP(pc,s);
-	for (j = 0; j < i; ++j) {
+	for (j = 0; j < i; j++) {
 	  Functor oldfunc = (Functor)(oldcode[0]);
 	  CODEADDR oldjmp = (CODEADDR)(oldcode[1]);
 	  if (oldfunc != NULL) {
@@ -1100,7 +1100,7 @@ RestoreClause(Clause *Cl, int mode)
 	startcode =
 #endif
 	  oldcode = (CELL *)NEXTOP(pc,s);
-	for (j = 0; j < i; ++j) {
+	for (j = 0; j < i; j++) {
 #if !USE_OFFSETS
 	  Term oldatom = oldcode[0];
 #endif
diff --git a/configure b/configure
index 973cbc65a..508c1d0f1 100755
--- a/configure
+++ b/configure
@@ -2444,6 +2444,7 @@ if test "$use_condor" = yes
 then
   use_malloc="yes"
   CC="condor_compile $CC"
+    yap_cv_readline="no"
 fi
 
 if test "$GCC" = "yes"
@@ -4611,6 +4612,14 @@ _ACEOF
 	    INSTALL_DLLS="#"
           fi
         fi
+	#do not use realloc() from HP-UX 10.20 together with MPI
+	if test ${target_os} = hpux10.20
+	then
+	  cat >>confdefs.h <<\_ACEOF
+#define MPI_AVOID_REALLOC 1
+_ACEOF
+
+	fi
 	;;
       *aix*)
 	# To actually use dlls in AIX I'd need to build YAP as a DLL first.
@@ -4836,7 +4845,7 @@ fi
 if test "$use_april" = "yes"
   then
    YAP_EXTRAS="$YAP_EXTRAS -DDEPTH_LIMIT=1 -DAPRIL"
-   LDFLAGS="$LDFLAGS -L./"
+   LDFLAGS="$LDFLAGS -L."
    LIBS="$LIBS -lApril"
 fi
 
diff --git a/configure.in b/configure.in
index f09270350..4dc465793 100644
--- a/configure.in
+++ b/configure.in
@@ -168,6 +168,8 @@ if test "$use_condor" = yes
 then
   use_malloc="yes"
   CC="condor_compile $CC"
+  dnl no readline with condor.
+  yap_cv_readline="no"
 fi
 
 dnl Compilation Flags
diff --git a/m4/Yap.h.m4 b/m4/Yap.h.m4
index c947d7ff5..c9fa920a3 100644
--- a/m4/Yap.h.m4
+++ b/m4/Yap.h.m4
@@ -10,7 +10,7 @@
 * File:		Yap.h.m4						 *
 * mods:									 *
 * comments:	main header file for YAP				 *
-* version:      $Id: Yap.h.m4,v 1.31 2002-09-23 17:06:13 vsc Exp $	 *
+* version:      $Id: Yap.h.m4,v 1.32 2002-10-10 05:58:49 vsc Exp $	 *
 *************************************************************************/
 
 #include "config.h"
@@ -434,6 +434,9 @@ typedef enum {
   EXISTENCE_ERROR_SOURCE_SINK,
   EXISTENCE_ERROR_STREAM,
   INSTANTIATION_ERROR,
+  OUT_OF_HEAP_ERROR,
+  OUT_OF_STACK_ERROR,
+  OUT_OF_TRAIL_ERROR,
   PERMISSION_ERROR_ACCESS_PRIVATE_PROCEDURE,
   PERMISSION_ERROR_NEW_ALIAS_FOR_STREAM,
   PERMISSION_ERROR_CREATE_ARRAY,
@@ -762,6 +765,10 @@ typedef struct opcode_tab_entry {
 /******************* controlling the compiler ****************************/
 extern int      optimizer_on;
 
+/******************* storing error messages ****************************/
+#define MAX_ERROR_MSG_SIZE 256
+extern char      ErrorSay[MAX_ERROR_MSG_SIZE];
+
 /********************* how to write a Prolog term ***********************/
 
 /********* Prolog may be in several modes *******************************/
@@ -773,7 +780,8 @@ typedef enum {
   AbortMode =   8,		/* expecting to abort */
   InterruptMode = 16,		/* under an interrupt */
   InErrorMode = 32,		/* under an interrupt */
-  ConsoleGetcMode = 64		/* blocked reading from console */
+  ConsoleGetcMode = 64,		/* blocked reading from console */
+  ExtendStackMode = 128		/* trying to extend stack */
 } prolog_exec_mode;
 
 extern prolog_exec_mode      PrologMode;
diff --git a/pl/errors.yap b/pl/errors.yap
index da95b0d68..cab1e9a06 100644
--- a/pl/errors.yap
+++ b/pl/errors.yap
@@ -52,10 +52,13 @@ print_message(Level, Mss) :-
 	user:portray_message(Severity, Msg), !.
 '$print_message'(error,error(syntax_error(A,B,C,D,E,F),_)) :- !,
 	'$output_error_message'(syntax_error(A,B,C,D,E,F), 'SYNTAX ERROR').
-'$print_message'(error,error(Msg,[Info|local_sp(Where,Envs,CPs)])) :-
+'$print_message'(error,error(Msg,[Info|local_sp(Where,Envs,CPs)])) :- !,
 	'$prepare_loc'(Info,Where,Location),
 	'$output_error_message'(Msg, Location), !,
 	'$do_stack_dump'(Envs, CPs).
+% old format: don't want a stack dump.
+'$print_message'(error,error(Type,Where)) :- !,
+	'$output_error_message'(Type, Where).
 '$print_message'(error,Throw) :-
 	'$format'(user_error,"[ No handler for error ~w ]~n", [Throw]).
 '$print_message'(informational,M) :-
@@ -198,6 +201,8 @@ print_message(Level, Mss) :-
 	'$preprocess_stack'(Gs, NGs).
 '$beautify_hidden_goal'('$undefp',1,prolog,ClNo,Gs,NGs) :- !,
 	'$preprocess_stack'(Gs, NGs).
+'$beautify_hidden_goal'('$repeat',0,prolog,ClNo,Gs,[cl(repeat,0,prolog,ClNo)|NGs]) :- !,
+	'$preprocess_stack'(Gs, NGs).
 '$beautify_hidden_goal'('$consult',2,prolog,ClNo,Gs,[cl(consult,1,prolog,ClNo)|NGs]) :- !,
 	'$preprocess_stack'(Gs, NGs).
 '$beautify_hidden_goal'('$findall_with_common_vars',_,prolog,ClNo,Gs,[cl(findall,4,prolog,ClNo)|NGs]) :- !,
@@ -393,6 +398,15 @@ print_message(Level, Mss) :-
 '$output_error_message'(instantiation_error, Where) :-
 	'$format'(user_error,"[ INSTANTIATION ERROR- ~w: expected bound value ]~n",
 	[Where]).
+'$output_error_message'(out_of_heap_error, Where) :-
+	'$format'(user_error,"[ OUT OF HEAP SPACE ERROR- ~w ]~n",
+	[Where]).
+'$output_error_message'(out_of_stack_error, Where) :-
+	'$format'(user_error,"[ OUT OF STACK SPACE ERROR- ~w ]~n",
+	[Where]).
+'$output_error_message'(out_of_trail_error, Where) :-
+	'$format'(user_error,"[ OUT OF TRAIL SPACE ERROR- ~w ]~n",
+	[Where]).
 '$output_error_message'(permission_error(access,private_procedure,P), Where) :-
 	'$format'(user_error,"[ PERMISSION ERROR- ~w: cannot see clauses for ~w ]~n",
 	[Where,P]).