git --literal-pathspecs add -u says "fatal: pathspec ':/' did not match any files"

~/tmp/tmprepo$ git init
Initialized empty Git repository in /home/npostavs/tmp/tmprepo/.git/
~/tmp/tmprepo$ git --literal-pathspecs add -u
fatal: pathspec ':/' did not match any files
~/tmp/tmprepo$ git --version
git version 2.6.1

It was reported[1] that 2.0.2 and several following versions also fail
with the same error; I found that version 1.9.5 succeeds.

Adding a "." argument:

   git --literal-pathspecs add -u .

succeeds in all versions.

[1]: https://github.com/magit/magit/issues/2354#issuecomment-150665961