diff --git a/libr/core/cmd_debug.c b/libr/core/cmd_debug.c
index 127db3de38..6b045826a6 100644
--- a/libr/core/cmd_debug.c
+++ b/libr/core/cmd_debug.c
@@ -401,7 +401,7 @@ static void cmd_debug_pid(RCore *core, const char *input) {
 		"dpa", " <pid>", "Attach and select pid",
 		"dpe", "", "Show path to executable",
 		"dpf", "", "Attach to pid like file fd // HACK",
-		"dpk", " <pid> <signal>", "Send signal to process",
+		"dpk", " <pid> [<signal>]", "Send signal to process (default 0)",
 		"dpn", "", "Create new process (fork)",
 		"dpnt", "", "Create new thread (clone)",
 		"dpt", "", "List threads of current pid",
@@ -409,7 +409,7 @@ static void cmd_debug_pid(RCore *core, const char *input) {
 		"dpt=", "<thread>", "Attach to thread",
 		NULL};
 	switch (input[1]) {
-	case '-':
+	case '-': // "dp-"
 		if (input[2]== ' ') {
 			r_debug_detach (core->dbg, r_num_math (core->num, input+2));
 		} else {
@@ -420,15 +420,16 @@ static void cmd_debug_pid(RCore *core, const char *input) {
 		/* stop, print, pass -- just use flags*/
 		/* XXX: not for threads? signal is for a whole process!! */
 		/* XXX: but we want fine-grained access to process resources */
-		pid = atoi (input+2);
-		ptr = strchr (input, ' ');
-		sig = ptr? atoi (ptr+1): 0;
+		pid = atoi (input + 2);
 		if (pid > 0) {
+			ptr = r_str_chop_ro (input + 2);
+			ptr = strchr (ptr, ' ');
+			sig = ptr? atoi (ptr + 1): 0;
 			eprintf ("Sending signal '%d' to pid '%d'\n", sig, pid);
 			r_debug_kill (core->dbg, 0, false, sig);
 		} else eprintf ("cmd_debug_pid: Invalid arguments (%s)\n", input);
 		break;
-	case 'n':
+	case 'n': // dpn
 		eprintf ("TODO: debug_fork: %d\n", r_debug_child_fork (core->dbg));
 		break;
 	case 't': // "dpt"
@@ -448,7 +449,7 @@ static void cmd_debug_pid(RCore *core, const char *input) {
 			break;
 		}
 		break;
-	case 'a':
+	case 'a': // "dpa"
 		if (input[2]) {
 			r_debug_attach (core->dbg, (int) r_num_math (
 				core->num, input+2));
@@ -462,22 +463,22 @@ static void cmd_debug_pid(RCore *core, const char *input) {
 			(core->dbg->h && !core->dbg->h->canstep));
 		r_core_cmdf (core, "=!pid %d", core->dbg->pid);
 		break;
-	case 'f':
+	case 'f': // "dpf"
 		if (core->file && core->file->desc) {
 			r_debug_select (core->dbg, core->file->desc->fd, core->dbg->tid);
 		}
 		break;
-	case '=':
+	case '=': // "dp="
 		r_debug_select (core->dbg,
 			(int) r_num_math (core->num, input+2), core->dbg->tid);
 		break;
-	case '*':
+	case '*': // "dp*"
 		r_debug_pid_list (core->dbg, 0, 0);
 		break;
-	case 'j':
+	case 'j': // "dpj"
 		r_debug_pid_list (core->dbg, core->dbg->pid, 'j');
 		break;
-	case 'e':
+	case 'e': // "dpe"
 		{
 			int pid = (input[2] == ' ')? atoi(input+2): core->dbg->pid;
 			char *exe = r_sys_pid_to_path (pid);
diff --git a/libr/debug/p/debug_native.c b/libr/debug/p/debug_native.c
index 2dd4f5c88d..00e0fcd89c 100644
--- a/libr/debug/p/debug_native.c
+++ b/libr/debug/p/debug_native.c
@@ -226,7 +226,7 @@ static int r_debug_native_continue (RDebug *dbg, int pid, int tid, int sig) {
 	return -1;
 #else
 	void *data = (void*)(size_t)((sig != -1) ? sig : dbg->reason.signum);
-//eprintf ("SIG %d\n", dbg->reason.signum);
+	//eprintf ("continuing with signal %d ...\n", dbg->reason.signum);
 	return ptrace (PTRACE_CONT, pid, NULL, data) == 0;
 #endif
 }
@@ -290,9 +290,11 @@ static int r_debug_native_wait (RDebug *dbg, int pid) {
 		// XXX: this is blocking, ^C will be ignored
 		int ret = waitpid (pid, &status, 0);
 		if (ret == -1) {
+			r_sys_perror ("waitpid");
 			status = R_DEBUG_REASON_ERROR;
 		} else {
-			//printf ("status=%d (return=%d)\n", status, ret);
+			//printf ("r_debug_native_wait: status=%d (return=%d)\n", status, ret);
+
 			// TODO: switch status and handle reasons here
 			r_debug_handle_signals (dbg);
 
diff --git a/libr/debug/p/native/linux/linux_debug.c b/libr/debug/p/native/linux/linux_debug.c
index 4e5646d746..75a17501bc 100644
--- a/libr/debug/p/native/linux/linux_debug.c
+++ b/libr/debug/p/native/linux/linux_debug.c
@@ -67,7 +67,7 @@ int linux_step (RDebug *dbg) {
 	int ret = false;
 	ut64 addr = 0; /* should be eip */
 	//ut32 data = 0;
-	//printf("NATIVE STEP over PID=%d\n", pid);
+	//printf("NATIVE STEP over PID=%d\n", dbg->pid);
 	addr = r_debug_reg_get (dbg, "PC");
 	ret = ptrace (PTRACE_SINGLESTEP, dbg->pid,
 			(void*)(size_t)addr, 0);