Now to test the ROM that got built from the hello world example. When I looked for a debugging Genesis emulator compatible with Ubuntu, I first looked at the Tools page on SpritesMind. Its recommended "Gens KMod" emulator shows a screenshot with a 2003 copyright date. Gens was reportedly the source of much of FCEUX's debugging UI, but it appears to be no longer maintained.
Elsewhere I saw someone recommend Regen. Despite its being unethical software by the definition of some members of this forum, I decided to evaluate it. But I hit a snag when I read the included README file:
======================The build on the website is ten years old, making me fear NESticle/Genecyst-class accuracy. But this struck me as worse:
Regen/GTK+ 0.95 ReadMe
By AamirM, Copyright (C) 2009
You may use and/or redistribute Regen provided that you :The README file does not rigorously define "commercial purposes." However, the license of a different emulator-like software package, the Oracle VirtualBox Extension Pack Personal Use and Evaluation License, defines noncommercial use to "expressly exclude any use of the Product for commercial purposes or to operate, run, or act on behalf of or for the benefit of a business, organization, governmental organization, or educational institution." If Regen's definition of commercial use remotely matches Oracle's, this would rule out using Regen to test a Genesis-compatible program being developed with the intent of eventually distributing copies of the Genesis-compatible program on cartridge for a fee.
1) Do not modify and/or alter, in any way, the files included.
2) You distribute all the files you got originally with Regen.
3) You may not sell, lease, rent or otherwise seek to gain monetary profit from
4) You may not distribute Regen with ROM images unless you have the legal right
to distribute them.
5) You may not use Regen for commercial purposes.
I would have requested an account on http://gendev.spritesmind.net/forum/ in order to seek clarification of the commercial use clause or recommendation of a different emulator, but instead I got this error message:
General ErrorWhich debugging Genesis emulator for Linux or Wine is any good and allows use to test a commercial project?
SQL ERROR [ mysqli ]
Can't connect to MySQL server on 'mysql55-166.perso' (110) 
An sql error occurred while fetching this page. Please contact an administrator if this problem persists.