According to this thread: ESP continually resetting. Any ideas? - #15 by danbates - the “correct” esp8266 board package to use with Arduino is version 2.4.2. I was using the latest, which is 2.5.2, so I downgraded it. This now doesn’t build, lots of errors as below.
C:\Users\PLC\ArduinoData\packages\esp8266\hardware\esp8266\2.4.2/tools/sdk/lib\libstdc++.a(ios-inst.o): In function `std::basic_ios<char, std::char_traits >::clear(std::_Ios_Iostate)’:
/Users/igrokhotkov/e/ESPTools/crosstool-NG/.build/xtensa-lx106-elf/build/build-cc-gcc-final/xtensa-lx106-elf/libstdc+±v3/include/bits/basic_ios.tcc:122: undefined reference to `std::__throw_ios_failure(char const*)’
C:\Users\PLC\ArduinoData\packages\esp8266\hardware\esp8266\2.4.2/tools/sdk/lib\libstdc++.a(c++locale.o):(.literal.ZNSt6locale5facet18_S_create_c_localeERPiPKcS1+0x4): undefined reference to `std::__throw_runtime_error(char const*)’
C:\Users\PLC\ArduinoData\packages\esp8266\hardware\esp8266\2.4.2/tools/sdk/lib\libstdc++.a(c++locale.o): In function `std::locale::facet::_S_create_c_locale(int*&, char const*, int*)’:
/Users/igrokhotkov/e/ESPTools/crosstool-NG/.build/xtensa-lx106-elf/build/build-cc-gcc-final/xtensa-lx106-elf/libstdc+±v3/src/c++98/c++locale.cc:207: undefined reference to `std::__throw_runtime_error(char const*)’
collect2.exe: error: ld returned 1 exit status