I downloaded Git source and installed it in a non-standard path. All the Git options have a `-h` option but the documentation listed there is very terse and many options are missing. I'd like the full documentation but am unable to find it. When I run `git help log` or `git log --help` I get the following error:

```
No manual entry for git-log

```

I've tried adding every path imaginable to `PATH` and `MANPATH` but it does no good, I still get these pesky errors. How can I get `git <option> --help` to work?