Undefined reference in WString library method

yona_gy · February 11, 2025, 9:02pm

Hello, all,
After integration of ESP NOW into a system that before used Serial1 as a communication channel I started to get the attached error notice. I don’t know the WString.h and WString.cpp because they are too deep in the technology. Will some kindly explain the reason of this?

Best regards
Yona Gy

C:/Users/USER/AppData/Local/Arduino15/packages/esp32/tools/esp-rv32/2405/bin/…/lib/gcc/riscv32-esp-elf/13.2.0/…/…/…/…/riscv32-esp-elf/bin/ld.exe:C:\Users\USER\AppData\Local\arduino\sketches\A7272F29DD22239C14FE451B83C3B0BE\sketch\SWtractorCombined_V1.0.ino.cpp.o: in function StringSumHelper::~StringSumHelper()': C:\Users\USER\AppData\Local\Arduino15\packages\esp32\hardware\esp32\3.1.1\cores\esp32/WString.h:399:(.text._Z4loopv+0x7c): undefined reference to gpIoClass::MachineSide()’
collect2.exe: error: ld returned 1 exit status

PJ_Glasso · February 11, 2025, 9:20pm

Hi there,

So which BSP are you using? You may need to roll it back to get the older LIB’s to run.
HTH
GL PJ