Bitcoin Core v0.21.1 has no problem for solo miner. mining cmd: getblocktemplate and submitblock got no changed and work well.
cgminer 4.11.1 need to fix it to work on gbt_solo mode. The cgminer got three work modes: has_stratum, has_gbt and gbt_solo.
I found it is very hard to run c code when segment faults often pump out. You have to work out yourself as solo users.
And by the way, I am just using my desktop computer for lotto solo mining. No other dedicated device!
The latest error message is: No servers could be used. Exiting.
(oh my goodness! I am still solo mining. Do i still need a server! ?)
I read from a reddit post that Virtualbox can be installed to create a stratum server. Did you use Virtualbox?
Everything you are attempting here is plain wrong.
Forget mining BTC with a PC, those days are over and have been for a decade.
If you want to get into solo mining of bitcoin then go and buy an entry level ASIC miner, there's litterally no other entry point for mining bitcoin these days.
There's plenty of devices to choose from Gekko Science Compac A1, Compac F etc or one of the many BitAxe devices.
Mining solo with anything less than 1TH/s is a waste of time and even at that level you'll be rolling the dice with really long odds.
Do a bit more research before you commit to such ventures.
If all you're interested in doing is burning money then sure waste your time setting up a PC with a high end GPU and maybe achieve 1-2 GH/s if you're lucky.
PC's might be suitable for Altcoin mining but forget it for BTC.
Thanks for your kind advice! And all other guys. thanks to you too!