adding unstaged changes when not in "work tree" yields only ambiguous error

[zenodotus280]

Describe the bug
When staging changes:

staging all error:
git error:invalid path: 'my-path-here'; class=Index (10)

A git repository is created using the --git-dir=/path/to/$FOLDER which will create the standard .git contents separate from the working files. If inside this folder gitui will not complain and will incorrectly show unstaged changes and not give suitable errors.

To Reproduce

mkdir -p ~/working_tree ~/git_folder && cd ~/working_tree
git init --git-dir ~/git_folder
touch readme.txt && git commit -a -c "init"
cd ~/.git_folder
git status
    # fatal: this operation must be run in a work tree
# gitui > "a" to add all files > error as specified at the top

Expected behavior
A clear and concise error similar to regular git commands.

Context (please complete the following information):

• OS/Distro + Version: Arch / EndeavourOS
• GitUI Version: nightly 2024-04-15
• Rust version: 1.27.0

Additional context
I expect many more commands to fail for similar reasons. No others tested. The porcelain git commands give a more operable error.