ESP-12F crash when upgrading from 2.4.2 to 2.5.0 or later

[OmarAlkassab]

Basic Infos

• This issue complies with the issue POLICY doc.
• I have read the documentation at readthedocs and the issue is not addressed there.
• I have tested that the issue is present in current master branch (aka latest git).
• I have searched the issue tracker for a similar issue.
• If there is a stack dump, I have decoded it.
• I have filled out all fields below.

Platform

• Hardware: [ESP-12]
• Core Version: [2.5.x]
• Development Env: [Platformio]
• Operating System: [Windows]

Settings in IDE

• Module: [Generic ESP8266 Module]
• Flash Mode: [dio]
• Flash Size: [4MB/1MB SPIFFS]
• lwip Variant: [v2 Lower Memory]
• Reset Method: [ck]
• Flash Frequency: [40Mhz]
• CPU Frequency: [80Mhz]
• Upload Using: [SERIAL]
• Upload Speed: [921600] (serial upload only)

Problem Description

When migrating from core 2.4.2 to 2.5.x, my code cause the esp to crash.
Note: the code has more than this code, but I putted the instructions that run before crash.

MCVE Sketch

#include <Arduino.h>

#include <ESP8266HTTPClient.h>
#include <ESP8266WiFi.h>
#include <ESP8266mDNS.h>
#include "ESP8266httpUpdate.h"
#include <ESP8266WiFiMulti.h>
#include <ESP8266WebServer.h>

#include <WiFiUdp.h>
#include <DNSServer.h>

#include <FS.h>
#include <EEPROM.h>

#include <PubSubClient.h>
#include <ArduinoOTA.h>

#include <TaskScheduler.h>
#include <Ticker.h>

ESP8266WebServer LocalWebServer(80);

void handleHome()
{
  Debug.println("handleHome");
  String s = HOME_page;   //HOME_page is in PROGMEM
  LocalWebServer.send(200, "text/html", s); //Send web page
}

void setup() {
  LocalWebServer.on("/", handleHome);
}

void loop() {
  LocalWebServer.handleClient();
}

Debug Messages

handleHome

Exception 3: LoadStoreError: Processor internal physical address or data error during load or store
PC: 0x402205a4: _scanf_float at /home/earle/src/esp-quick-toolchain/repo/newlib/newlib/libc/stdio/nano-vfscanf_float.c line 217
EXCVADDR: 0x402598e7

[OmarAlkassab]

@devyte any suggestion?

[OmarAlkassab]

is that enough?
@devyte
@JAndrassy

[Pablo2048]

You are kidding right? You have checked If there is a stack dump, I have decoded it. but decoded stack is missing, MCVE wont compile, so guess yourself - is that enough?

[OmarAlkassab]

Sorry I forgot to copy and paste it! because I return back to core 2.4.2
I will update the core then reproduce the issue, then edit it.

[OmarAlkassab]

I debugged my code, and I discovered that the problem in use of PROGMEM

[OmarAlkassab]

I solved the issue by using the String s = FPSTR(HOME_page); instead of String s = HOME_page;

[Pablo2048]

Is there any reason why you can not use send_P() method? Copying data rom progmem and then sending the same data to the client doesn't look very smart to me...

[OmarAlkassab]

@Pablo2048, You are right, I edit my code and use send_P() instead.
Many thanks.