where are the docs for $HG environment variable?

[Forest]

Thomas Arendsen Hein wrote:

>> Where is $HG documented?  I don't see it in the latest man pages, and I'd
>> like to know the rules for its use.  Which commands require it?  Can I use
>> an hgrc entry instead of setting an environment variable?
>
>It is documented in:
>man hg

Looking at Docs/hg.1.html from the binary Windows distribution, and I don't
see HG listed in the ENVIRONMENT VARIABLES section.  The same goes for
help.txt.  Looking at hg.1.txt, I don't see an ENVIRONMENT VARIABLES section
at all.

>hg help env

Ah, there it is, but it doesn't mention that I have to manually set the HG
variable for 'hg view' to work.

>You added
>@set HG=C:\location\of\hg.exe
>
>Do you use hg on Windows or some other system?

Sorry, I thought I had mentioned this was a windows box in my original post.
Windows 2000, to be more specific.  I also use hg on linux, where I didn't
have this problem.

>What is special in your setup that hg can't find its own executable?

I think Evan Powers' reply answers that question.  In short, hg's executable
path detection is broken on Windows.