C++ forbits converting a string const to char

[SVR1936]

C:\Users\saura\OneDrive\Documents\Arduino\libraries\FirebaseArduino\src\FirebaseHttpClient_Esp8266.cpp: In member function 'virtual void FirebaseHttpClientEsp8266::begin(const string&)': C:\Users\saura\OneDrive\Documents\Arduino\libraries\FirebaseArduino\src\FirebaseHttpClient_Esp8266.cpp:47:50: error: no matching function for call to 'begin(const char*, const char [60])' 47 | http_.begin(url.c_str(), kFirebaseFingerprint); | ^ In file included from C:\Users\saura\OneDrive\Documents\Arduino\libraries\FirebaseArduino\src\FirebaseHttpClient_Esp8266.cpp:9: C:\Users\saura\AppData\Local\Arduino15\packages\esp8266\hardware\esp8266\3.1.1\libraries\ESP8266HTTPClient\src/ESP8266HTTPClient.h:166:10: note: candidate: 'bool HTTPClient::begin(String, uint16_t, String)' (near match) 166 | bool begin(String host, uint16_t port, String uri = "/") attribute ((error("obsolete API, use ::begin(WiFiClient, host, port, uri)"))); | ^~~~~ C:\Users\saura\AppData\Local\Arduino15\packages\esp8266\hardware\esp8266\3.1.1\libraries\ESP8266HTTPClient\src/ESP8266HTTPClient.h:166:10: note: conversion of argument 2 would be ill-formed: C:\Users\saura\OneDrive\Documents\Arduino\libraries\FirebaseArduino\src\FirebaseHttpClient_Esp8266.cpp:47:30: error: invalid conversion from 'const char*' to 'uint16_t' {aka 'short unsigned int'} [-fpermissive] 47 | http_.begin(url.c_str(), kFirebaseFingerprint); | ^~~~~~~~~~~~~~~~~~~~ | | | const char* In file included from C:\Users\saura\OneDrive\Documents\Arduino\libraries\FirebaseArduino\src\FirebaseHttpClient_Esp8266.cpp:9: C:\Users\saura\AppData\Local\Arduino15\packages\esp8266\hardware\esp8266\3.1.1\libraries\ESP8266HTTPClient\src/ESP8266HTTPClient.h:167:10: note: candidate: 'bool HTTPClient::begin(String, const uint8_t*)' (near match) 167 | bool begin(String url, const uint8_t httpsFingerprint[20]) attribute ((error("obsolete API, use ::begin(WiFiClientSecure, ...)"))); | ^~~~~ C:\Users\saura\AppData\Local\Arduino15\packages\esp8266\hardware\esp8266\3.1.1\libraries\ESP8266HTTPClient\src/ESP8266HTTPClient.h:167:10: note: conversion of argument 2 would be ill-formed: C:\Users\saura\OneDrive\Documents\Arduino\libraries\FirebaseArduino\src\FirebaseHttpClient_Esp8266.cpp:47:30: error: invalid conversion from 'const char*' to 'const uint8_t*' {aka 'const unsigned char*'} [-fpermissive] 47 | http_.begin(url.c_str(), kFirebaseFingerprint); | ^~~~~~~~~~~~~~~~~~~~ | | | const char* C:\Users\saura\OneDrive\Documents\Arduino\libraries\FirebaseArduino\src\FirebaseHttpClient_Esp8266.cpp: In member function 'virtual void FirebaseHttpClientEsp8266::begin(const string&, const string&)': C:\Users\saura\OneDrive\Documents\Arduino\libraries\FirebaseArduino\src\FirebaseHttpClient_Esp8266.cpp:51:60: error: invalid conversion from 'const char*' to 'const uint8_t*' {aka 'const unsigned char*'} [-fpermissive] 51 | http_.begin(host.c_str(), kFirebasePort, path.c_str(), kFirebaseFingerprint); | ^~~~~~~~~~~~~~~~~~~~ | | | const char* In file included from C:\Users\saura\OneDrive\Documents\Arduino\libraries\FirebaseArduino\src\FirebaseHttpClient_Esp8266.cpp:9: C:\Users\saura\AppData\Local\Arduino15\packages\esp8266\hardware\esp8266\3.1.1\libraries\ESP8266HTTPClient\src/ESP8266HTTPClient.h:168:70: note: initializing argument 4 of 'bool HTTPClient::begin(String, uint16_t, String, const uint8_t*)' 168 | bool begin(String host, uint16_t port, String uri, const uint8_t httpsFingerprint[20]) attribute ((error("obsolete API, use ::begin(WiFiClientSecure, ...)"))); | ~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~ C:\Users\saura\OneDrive\Documents\Arduino\libraries\FirebaseArduino\src\Firebase.cpp: In member function 'int FirebaseRequest::sendRequest(const string&, const string&, char*, const string&, const string&)': C:\Users\saura\OneDrive\Documents\Arduino\libraries\FirebaseArduino\src\Firebase.cpp:78:1: error: no return statement in function returning non-void [-Werror=return-type] 78 | } | ^ C:\Users\saura\OneDrive\Documents\Arduino\libraries\FirebaseArduino\src\Firebase.cpp: In member function 'void FirebaseStream::startStreaming(const string&, const string&, const string&)': C:\Users\saura\OneDrive\Documents\Arduino\libraries\FirebaseArduino\src\Firebase.cpp:91:16: warning: ISO C++ forbids converting a string constant to 'char*' [-Wwrite-strings] 91 | analyzeError("STREAM", status, path_with_auth); | ^~~~~~~~ cc1plus.exe: some warnings being treated as errors C:\Users\saura\OneDrive\Documents\Arduino\libraries\FirebaseArduino\src\FirebaseArduino.cpp: In member function 'String FirebaseArduino::push(const String&, const ArduinoJson::JsonVariant&)': C:\Users\saura\OneDrive\Documents\Arduino\libraries\FirebaseArduino\src\FirebaseArduino.cpp:65:54: warning: ISO C++ forbids converting a string constant to 'char*' [-Wwrite-strings] 65 | int status = req_.get()->sendRequest(host_, auth_, "POST", path.c_str(), buf); | ^~~~~~ C:\Users\saura\OneDrive\Documents\Arduino\libraries\FirebaseArduino\src\FirebaseArduino.cpp: In member function 'void FirebaseArduino::set(const String&, const ArduinoJson::JsonVariant&)': C:\Users\saura\OneDrive\Documents\Arduino\libraries\FirebaseArduino\src\FirebaseArduino.cpp:94:41: warning: ISO C++ forbids converting a string constant to 'char*' [-Wwrite-strings] 94 | req_.get()->sendRequest(host_, auth_, "PUT", path.c_str(), buf); | ^~~~~ C:\Users\saura\OneDrive\Documents\Arduino\libraries\FirebaseArduino\src\FirebaseArduino.cpp: In member function 'void FirebaseArduino::getRequest(const String&)': C:\Users\saura\OneDrive\Documents\Arduino\libraries\FirebaseArduino\src\FirebaseArduino.cpp:101:41: warning: ISO C++ forbids converting a string constant to 'char*' [-Wwrite-strings] 101 | req_.get()->sendRequest(host_, auth_, "GET", path.c_str()); | ^~~~~ C:\Users\saura\OneDrive\Documents\Arduino\libraries\FirebaseArduino\src\FirebaseArduino.cpp: In member function 'virtual void FirebaseArduino::remove(const String&)': C:\Users\saura\OneDrive\Documents\Arduino\libraries\FirebaseArduino\src\FirebaseArduino.cpp:147:41: warning: ISO C++ forbids converting a string constant to 'char*' [-Wwrite-strings] 147 | req_.get()->sendRequest(host_, auth_, "DELETE", path.c_str()); | ^~~~~~~~

[TrickSumo]

In case anyone face same problem in future, downgrading ESP8266 board and ArduinoJSON library is only option as of now (September 2023). Steps to do same:- https://www.youtube.com/watch?v=m3Xb9GB9SI8