It possible to hard fork a private network without resyncing chain from scratch?

I am able to hard fork my private chain into first Constantinople and than to Istanbul, please see the answer for it. My approach is: I have updated geth to its highest version I have kept the go-ethereum/params/config.go file as it is I have updated the genesis.json file by adding “constantinopleBlock”: 2862930, “petersburgBlock”: 2862930, and…

Remix IDE: How to debug a contract having a function with a argument & for Loop

I am trying to debug a contract on Remix IDE: pragma solidity ^0.5.1; contract DebuggerSampleContract{ int counter = 10; function LoopCounter(int _input) public view returns (int) { int returnValue; for(; _input <counter; _input++) { returnValue += _input; } returnValue; } } I selected following steps: 1. Solidity Compiler, 2. Compile DebuggerSampleContract.sol, 3. Deployand Run Transactions,…