diff --git a/moo/configure.ac b/moo/configure.ac
index ad9d667..c3787b5 100644
--- a/moo/configure.ac
+++ b/moo/configure.ac
@@ -174,6 +174,7 @@ AC_CHECK_FUNCS([makecontext swapcontext getcontext setcontext])
 AC_CHECK_FUNCS([clock_nanosleep nanosleep usleep])
 AC_CHECK_FUNCS([snprintf _vsnprintf _vsnwprintf strerror_r])
 AC_CHECK_FUNCS([accept4])
+AC_CHECK_FUNCS([isatty])
 
 AC_CHECK_LIB([dyncall_s], [dcNewCallVM], 
 	[
diff --git a/moo/lib/exec.c b/moo/lib/exec.c
index 2123b8c..d386d2d 100644
--- a/moo/lib/exec.c
+++ b/moo/lib/exec.c
@@ -125,7 +125,7 @@ static MOO_INLINE const char* proc_state_to_string (int state)
 #	define __PRIMITIVE_NAME__ (&__FUNCTION__[0])
 #endif
 
-static int delete_from_sem_io (moo_t* moo, moo_oop_semaphore_t sem);
+static int delete_from_sem_io (moo_t* moo, moo_oop_semaphore_t sem, int force);
 static void signal_io_semaphore (moo_t* moo, moo_ooi_t io_handle, moo_ooi_t mask);
 static int send_message (moo_t* moo, moo_oop_char_t selector, int to_super, moo_ooi_t nargs);
 static int send_message_with_str (moo_t* moo, const moo_ooch_t* nameptr, moo_oow_t namelen, int to_super, moo_ooi_t nargs);
@@ -168,12 +168,14 @@ static MOO_INLINE void vm_cleanup (moo_t* moo)
 
 			if (moo->sem_io_tuple[sem_io_index].sem[MOO_SEMAPHORE_IO_TYPE_INPUT])
 			{
-				delete_from_sem_io (moo, moo->sem_io_tuple[sem_io_index].sem[MOO_SEMAPHORE_IO_TYPE_INPUT]);
+				delete_from_sem_io (moo, moo->sem_io_tuple[sem_io_index].sem[MOO_SEMAPHORE_IO_TYPE_INPUT], 1);
 			}
 			if (moo->sem_io_tuple[sem_io_index].sem[MOO_SEMAPHORE_IO_TYPE_OUTPUT])
 			{
-				delete_from_sem_io (moo, moo->sem_io_tuple[sem_io_index].sem[MOO_SEMAPHORE_IO_TYPE_OUTPUT]);
+				delete_from_sem_io (moo, moo->sem_io_tuple[sem_io_index].sem[MOO_SEMAPHORE_IO_TYPE_OUTPUT], 1);
 			}
+
+			MOO_ASSERT (moo, moo->sem_io_map[i] <= -1);
 		}
 		else 
 		{
@@ -1247,7 +1249,7 @@ static int add_to_sem_io (moo_t* moo, moo_oop_semaphore_t sem, moo_ooi_t io_hand
 	return 0;
 }
 
-static int delete_from_sem_io (moo_t* moo, moo_oop_semaphore_t sem)
+static int delete_from_sem_io (moo_t* moo, moo_oop_semaphore_t sem, int force)
 {
 	moo_ooi_t index;
 	moo_ooi_t new_mask, io_handle, io_type;
@@ -1280,7 +1282,15 @@ static int delete_from_sem_io (moo_t* moo, moo_oop_semaphore_t sem)
 	if (x <= -1) 
 	{
 		MOO_LOG3 (moo, MOO_LOG_WARN, "Failed to delete an IO semaphore at index %zd of type %d on handle %zd\n", index, (int)io_type, io_handle);
-		return -1;
+		if (!force) return -1;
+
+		/* NOTE: 
+		 *   this means there could be some issue handling the file handles.
+		 *   the file handle might have been closed before reaching here.
+		 *   assuming the callback works correctly, it's not likely that the
+		 *   underlying operating system returns failure for no reason.
+		 *   i should inspect the overall vm implementation */
+		MOO_LOG3 (moo, MOO_LOG_ERROR, "Forcibly unmapping the handle %zd despite failure\n", index, (int)io_type, io_handle);
 	}
 
 	MOO_LOG3 (moo, MOO_LOG_DEBUG, "Deleted an IO semaphore at index %zd of type %d on handle %zd\n", index, (int)io_type, io_handle);
@@ -2613,7 +2623,7 @@ static moo_pfrc_t pf_system_remove_semaphore (moo_t* moo, moo_ooi_t nargs)
 		MOO_ASSERT (moo, MOO_OOP_IS_SMOOI(sem->io_handle) && MOO_OOP_TO_SMOOI(sem->io_handle) >= 0);
 		MOO_ASSERT (moo, MOO_OOP_IS_SMOOI(sem->io_type));
 
-		if (delete_from_sem_io (moo, sem) <= -1)
+		if (delete_from_sem_io(moo, sem, 0) <= -1)
 		{
 			const moo_ooch_t* oldmsg = moo_backuperrmsg(moo);
 			moo_seterrbfmt (moo, moo->errnum, "cannot delete the handle %zd from the multiplexer - %js", MOO_OOP_TO_SMOOI(sem->io_handle), oldmsg);
diff --git a/moo/lib/logfmt.c b/moo/lib/logfmt.c
index 05b9d9b..2a30c7f 100644
--- a/moo/lib/logfmt.c
+++ b/moo/lib/logfmt.c
@@ -614,7 +614,12 @@ moo_ooi_t moo_logbfmt (moo_t* moo, moo_oow_t mask, const moo_bch_t* fmt, ...)
 
 	if (moo->log.default_type_mask & MOO_LOG_ALL_TYPES) 
 	{
-		mask &= ~MOO_LOG_UNTYPED;
+		/* if a type is given, it's not untyped any more.
+		 * mask off the UNTYPED bit */
+		mask &= ~MOO_LOG_UNTYPED; 
+
+		/* if the default_type_mask has the UNTYPED bit on,
+		 * it'll get turned back on */
 		mask |= (moo->log.default_type_mask & MOO_LOG_ALL_TYPES);
 	}
 
diff --git a/moo/lib/main.c b/moo/lib/main.c
index fbbfef5..fdad514 100644
--- a/moo/lib/main.c
+++ b/moo/lib/main.c
@@ -197,6 +197,7 @@ struct xtn_t
 
 	int logfd;
 	int logmask;
+	int logfd_istty;
 
 #if defined(_WIN32)
 	HANDLE waitable_timer;
@@ -777,6 +778,14 @@ static void log_write (moo_t* moo, moo_oow_t mask, const moo_ooch_t* msg, moo_oo
 		write_all (logfd, ts, tslen);
 	}
 
+
+	if (xtn->logfd_istty)
+	{
+		if (mask & MOO_LOG_FATAL) write_all (logfd, "\x1B[1;31m", 7);
+		else if (mask & MOO_LOG_ERROR) write_all (logfd, "\x1B[1;36m", 7);
+		else if (mask & MOO_LOG_WARN) write_all (logfd, "\x1B[1;33m", 7);
+	}
+
 #if defined(MOO_OOCH_IS_UCH)
 	msgidx = 0;
 	while (len > 0)
@@ -815,6 +824,11 @@ static void log_write (moo_t* moo, moo_oow_t mask, const moo_ooch_t* msg, moo_oo
 	write_all (logfd, msg, len);
 #endif
 
+	if (xtn->logfd_istty)
+	{
+		if (mask & (MOO_LOG_FATAL | MOO_LOG_ERROR | MOO_LOG_WARN)) write_all (logfd, "\x1B[0m", 4);
+	}
+
 #endif
 }
 
@@ -2022,6 +2036,7 @@ static void close_moo (moo_t* moo)
 	{
 		close (xtn->logfd);
 		xtn->logfd = -1;
+		xtn->logfd_istty = 0;
 	}
 	moo_close (moo);
 }
@@ -2091,6 +2106,10 @@ static int handle_logopt (moo_t* moo, const moo_bch_t* str)
 		return -1;
 	}
 
+#if defined(HAVE_ISATTY)
+	xtn->logfd_istty = isatty(xtn->logfd))
+#endif
+
 	if (str != xstr) moo_freemem (moo, xstr);
 	return 0;
 }
@@ -2263,6 +2282,7 @@ int main (int argc, char* argv[])
 
 	xtn = moo_getxtn (moo);
 	xtn->logfd = -1;
+	xtn->logfd_istty = 0;
 
 	if (logopt)
 	{