A lot of us might experience similar things, but this seems somewhat unique.
He has a large amount of original low level code where he's the only maintainer, that doesn't work with standard dev tools.
A lot of non-hacker devs would probably have lost interest in, or totally rewritten a project to match modern APIs, long before it was likely to break like that.
Lots of people seem to be offering to help, but that doesn't seem to be what he wants.
He mentions a feeling of fate telling him to move on, hiking, and staying healthy, which seems much more interesting and important.