Output from custom target *very* slow to appear in the terminal

[adbancroft]

• PlatformIO Core.
  If you’ve found a bug, please provide an information below.

Goal

Add a custom target that launches a simulator: simavr in my case.

Configuration

Operating system: Window 10 64 bit Version 1909

PlatformIO Version (platformio --version): PlatformIO Core, version 5.2.0a6

Description of problem

Simulator output is incredibly slow to echo in the terminal: up to the point it looks like nothing is happening. If I wait long enough (minutes) it eventually appears.

Running simavr on it's own produces output line by line.

Steps to Reproduce

1. Setup a project using the ini, cpp & python script below.
2. Build
3. Launch the 'Simulate' custom target. E.g. pio run -t Simulate

Actual Results

Simulator output doesn't appear in the terminal

Expected Results

Simulator output (to stdout & stderr) is echoed in the terminal as soon as the child simavr process prints to stdout/stderr.

If problems with PlatformIO Build System:

The content of platformio.ini:

[env:megaatmega2560]
platform = atmelavr
board = megaatmega2560
framework = arduino
extra_scripts = simavr_env.py

Source file to reproduce issue:

#include <Arduino.h>

int counter = 0;

void setup() {
  Serial.begin(9600);
  Serial.println("TESTING");
}

void loop() {
  if (counter % 10 == 0) {
    Serial.println(counter); 
  } else {
    Serial.print(counter); Serial.print("-");
  }
  counter++;
  delay(100);
}

Additional info

• Custom python script
• slow-output-from-custom-target.zip

[valeros]

Hi @adbancroft ! It seems your extra script is no longer available. Could you please upload it somewhere so I can reproduce the issue?

[adbancroft]

@valeros Original link updated.

Also here: https://github.com/ridiculousfish/libdivide/blob/master/test/avr/simavr_env.py

[ivankravets]

Duplicate of buserror/simavr#489