Added more debugging to stdout writes.

src/pv/loop.c

@@ -192,6 +192,7 @@ int pv_main_loop(pvstate_t state)
 				&& (0 == state->control.rate_limit))) {
 				cansend = state->control.size - total_written;
 				if (0 >= cansend) {
+					debug("%s", "write limit reached (size explicitly set) - setting EOF flags");
 					eof_in = true;
 					eof_out = true;
 				}
@@ -207,6 +208,7 @@ int pv_main_loop(pvstate_t state)
 
 		/* End on write error. */
 		if (written < 0) {
+			debug("%s: %s", "write error from pv_transfer", strerror(errno));
 			if (state->control.cursor)
 				pv_crs_fini(state);
 			return state->status.exit_status;
@@ -344,6 +346,9 @@ int pv_main_loop(pvstate_t state)
 		transferred_since_last = 0;
 	}
 
+	debug("%s: %s=%s, %s=%s", "loop ended", "eof_in", eof_in ? "true" : "false", "eof_out",
+	      eof_out ? "true" : "false");
+
 	if (state->control.cursor) {
 		pv_crs_fini(state);
 	} else {

src/pv/transfer.c

@@ -678,12 +678,15 @@ static int pv__transfer_write(pvstate_t state, bool *eof_in, bool *eof_out, long
 
 #else				/* ! HAVE_SETITIMER */
 		(void) alarm(1);
+		debug("%s", "setting alarm");
 #endif				/* HAVE_SETITIMER */
+		debug("%s: %ld %s", "beginning write attempt", (long) (state->transfer.to_write), "bytes");
 		nwritten = pv__transfer_write_repeated(STDOUT_FILENO,
 						       state->transfer.transfer_buffer +
 						       state->transfer.write_position,
 						       (size_t) (state->transfer.to_write),
 						       state->control.sync_after_write);
+		debug("%s: %ld", "bytes written", (long) nwritten);
 #if HAVE_SETITIMER
 		memset(&new_timer, 0, sizeof(new_timer));
 		new_timer.it_interval.tv_sec = 0;
@@ -696,6 +699,7 @@ static int pv__transfer_write(pvstate_t state, bool *eof_in, bool *eof_out, long
 
 		/*@+unrecog@ */
 #else				/* ! HAVE_SETITIMER */
+		debug("%s", "cancelling alarm");
 		(void) alarm(0);
 #endif				/* HAVE_SETITIMER */
 	}