Memory issue since IDF update

[luc-github]

Hi,
It seems since last idf sync (d27d297) there is a memory issue
before this commit you can have in a function : a static String variable
like static String s; without issue

after this commit if a call is done to the function having a static String then esp crash

My test code is SPIFFS_test.ino where I just added the static variable declaration, even not used it

void listDir(fs::FS &fs, const char * dirname, uint8_t levels){
	static String s;
    Serial.printf("Listing directory: %s\n", dirname);
   ...

Here the exception:
the first line is the ESP.getFreeHeap() to check memory

199016
Guru Meditation Error of type InstrFetchProhibited occurred on core  1. Exception was unhandled.
Register dump:
PC      : 0x00000000  PS      : 0x00060730  A0      : 0x800d355a  A1      : 0x3ffcf190  
A2      : 0x3ffc2750  A3      : 0x3f401229  A4      : 0x00000000  A5      : 0x0000ff00  
A6      : 0x00ff0000  A7      : 0xff000000  A8      : 0x800d345a  A9      : 0x3ffcf170  
A10     : 0x3ffc2750  A11     : 0x00000001  A12     : 0x3ffc9f7c  A13     : 0x0000ff00  
A14     : 0x00ff0000  A15     : 0xff000000  SAR     : 0x00000010  EXCCAUSE: 0x00000014  
EXCVADDR: 0x00000000  LBEG    : 0x4000c2e0  LEND    : 0x4000c2f6  LCOUNT  : 0xffffffff  

Backtrace: 0x00000000:0x3ffcf190 0x400d3557:0x3ffcf1b0 0x400d0d54:0x3ffcf1e0 0x400d103b:0x3ffcf250 0x400e471f:0x3ffcf280

may be it is linked to : espressif/esp-idf#1072 (comment)

[projectgus]

Thanks for reporting this. This problem is related to the updated toolchain, but not the same as the IDF issue linked above.

Have submitted a PR with a potential fix, please see if it solves the problem for you.

[luc-github]

Yes it seems solving the issue indeed - thank you so much

[me-no-dev]

merged,! :)