Re: `git rev-parse --is-inside-work-tree` and $GIT_WORK_TREE

John Keeping <john@keeping.me.uk> writes:

I didn't carefully read the other parts of the discussion, but this is not entirely correct.

The actual/intended rules are fairly simple.

 * With GIT_DIR (without GIT_WORK_TREE), you specify where the .git
   directory is, and refuse the "normal detection logic".  As you
   refuse the normal "where is the root of the working tree and its
   .git directory?" logic, Git uses the current directory as the
   root of the working tree.

 * But that means if you set GIT_DIR, you cannot work from a
   subdirectory of your working tree--you always have to run Git
   from the root level of your working tree.  This may be
   inconvenient.

 * That is why GIT_WORK_TREE exists.  It allows you to say "No, I am
   not at the root level but am in a subdirectory somewhere inside
   the working tree. The root level of the working tree is there
   above, not here".

So it is a misconfiguration if you only set GIT_WORK_TREE without setting GIT_DIR.

Also, if you set both and run Git from outside $GIT_WORK_TREE, even though Git may try to do its best to give you a reasonable behaviour [*1*], it is working by accident not by design (see the statement you are making by setting GIT_WORK_TREE in the third bullet above).

IOW, running from outside GIT_WORK_TREE is a misconfiguration.

[Footnote]

*1* Think what should happen when you are outside GIT_WORK_TREE and
    say this:

	$ git grep foo

    As you are not even inside the working tree, the command would
    not know in which subdirectory you want to find the string foo;
    the "reasonable behaviour" is to work on the whole working tree
    in this case.