I like that idea as well, sourecetree does that

Sourcetree doesn't have any issues with it, couldn't you include an option to grab a valid copy that's compatible, like the option to download a compatible version from your website that you guys compiled yourself, sourcetree does that. that's better than just telling the user "you're screwed, use a different application". or maybe just save us all the hassle and just ditch HG support if your having such a hard time supporting it.