How to correct gitdir/worktree paths across systemd-run path mappings?

[przepompownia]

In Debian I use systemd-run path mappings (https://github.com/przepompownia/dotnvim/blob/master/lib/nvim-isolated) because of NVIM_APPNAME restrictions. On the other side my dotnvim project is a submodule of the home directory. It contains plugins as sumbodules. I noticed "outside repository" error from Gitsigns when jumped (from checkhealth deprecation messages by gF) to such "internal" paths. My gitdirs are moved up by git submodule absorbgitdirs.

In such case .git in lowest level repo becomes a file that contains a relative path to its gitdir gitconfig directory. Assume that the path accidentally exists (inside the container). Probably the worktree path is then read from that config. This is a real path and can differ from the original worktree.

I have created a minimal example that shows what happens:

init.lua:

local plugins = {
  gitsigns = 'https://github.com/lewis6991/gitsigns.nvim',
}

for name, url in pairs(plugins) do
  local install_path = '/tmp/nvim/site/pack/test/start/' .. name
  if vim.fn.isdirectory(install_path) == 0 then
    vim.fn.system { 'git', 'clone', '--depth=111', url, install_path }
  end
  vim.opt.runtimepath:append(install_path)
end

require('gitsigns').setup {
  debug_mode = true,
}

repro.sh for Linux with systemd

#!/usr/bin/env bash
set -e

nvimBinary="${NVIM_FROM_SRC_DIR:+$NVIM_FROM_SRC_DIR/bin/}nvim"
reproDir="$PWD"

toplevel="$1"

createRepos() (
    exampleUrl='https://github.com/sarcasticadmin/empty-repo'
    cd "$toplevel"
    git init
    git submodule add "$exampleUrl"
    cd 'empty-repo'
    git submodule add "$exampleUrl"
    git submodule absorbgitdirs

    cd "$reproDir"
)

if [[ -z $toplevel ]]; then
    toplevel="$(mktemp -d)"
    createRepos
fi

printf 'Next time run "%s %s"\n' $0 "$toplevel" >&2

systemd-run --quiet --user --pty --pipe --same-dir \
    --property=BindPaths="${toplevel}/empty-repo/empty-repo/:${toplevel}/empty-repo2/empty-repo/" \
    "$nvimBinary" --clean -u init.lua \
    "${toplevel}/empty-repo2/empty-repo/README.md"

In short, ${toplevel}/empty-repo/empty-repo/ in the real environment is available as ${toplevel}/empty-repo2/empty-repo/ in the "container".

Is it possible to configure Gitsigns in such case for correct worktree and gitdir detection?

115.37 D run_job: git --no-pager --no-optional-locks --literal-pathspecs -c gc.auto=0 rev-parse --show-toplevel --absolute-git-dir --abbrev-ref HEAD
117.43 D run_job: git --no-pager --no-optional-locks --literal-pathspecs -c gc.auto=0 rev-parse --show-toplevel --absolute-git-dir --abbrev-ref HEAD
121.41 D run_job: git --no-pager --no-optional-locks --literal-pathspecs -c gc.auto=0 --git-dir /tmp/tmp.RXP1YyDuHi/.git/modules/empty-repo/modules/empty-repo --work-tree /tmp/tmp.RXP1YyDuHi/empty-repo/empty-repo config user.name
125.16 D run_job: git --no-pager --no-optional-locks --literal-pathspecs -c gc.auto=0 --git-dir /tmp/tmp.RXP1YyDuHi/.git/modules/empty-repo/modules/empty-repo --work-tree /tmp/tmp.RXP1YyDuHi/empty-repo/empty-repo -c core.quotepath=off ls-fi
les --stage --others --exclude-standard --eol /tmp/tmp.RXP1YyDuHi/empty-repo2/empty-repo/README.md
129.25 E .../nvim/site/pack/test/start/gitsigns/lua/gitsigns/git.lua<247>: fatal: /tmp/tmp.RXP1YyDuHi/empty-repo2/empty-repo/README.md: '/tmp/tmp.RXP1YyDuHi/empty-repo2/empty-repo/README.md' is outside repository at '/tmp/tmp.RXP1YyDuHi/emp
ty-repo/empty-repo'

stack traceback:
        ...site/pack/test/start/gitsigns/lua/gitsigns/debug/log.lua:134: in function 'eprint'
        ...site/pack/test/start/gitsigns/lua/gitsigns/debug/log.lua:141: in function 'eprint'
        .../nvim/site/pack/test/start/gitsigns/lua/gitsigns/git.lua:247: in function 'new'
        ...im/site/pack/test/start/gitsigns/lua/gitsigns/attach.lua:221: in function 'fn'
        .../site/pack/test/start/gitsigns/lua/gitsigns/debounce.lua:68: in function 'attach_throttled'
        ...im/site/pack/test/start/gitsigns/lua/gitsigns/attach.lua:374: in function <...im/site/pack/test/start/gitsigns/lua/gitsigns/attach.lua:373>

[lewis6991]

Honestly, I have no idea. You can see Gitsigns is trying to run:

git --no-pager --no-optional-locks --literal-pathspecs -c gc.auto=0 --git-dir /tmp/tmp.RXP1YyDuHi/.git/modules/empty-repo/modules/empty-repo --work-tree /tmp/tmp.RXP1YyDuHi/empty-repo/empty-repo -c core.quotepath=off ls-fi
les --stage --others --exclude-standard --eol /tmp/tmp.RXP1YyDuHi/empty-repo2/empty-repo/README.md

And for some reason that is failing. To get this to work, we need a git-ls-files command that works.

I'm assuming the gitdir and worktree in the above command is correct?

[przepompownia]

I guess that Gitsigns (or git - I not verified it) gets both values from .git and then config, while both are accessible:

 $ cat /tmp/tmp.3ybYm1K5lQ/empty-repo/empty-repo/.git
gitdir: ../../.git/modules/empty-repo/modules/empty-repo

 $ cat /tmp/tmp.3ybYm1K5lQ/empty-repo/empty-repo/../../.git/modules/empty-repo/modules/empty-repo/config
[core]
        repositoryformatversion = 0
        filemode = true
        bare = false
        logallrefupdates = true
        worktree = ../../../../../empty-repo/empty-repo
...

On the other side, if we remove 2 from the failing command, it works correctly, which means that the queried absolute path must match to those specified in --git and --work-tree. But look at making it relative:

 $ git --no-pager --no-optional-locks --literal-pathspecs -c gc.auto=0 --git-dir /tmp/tmp.pG92ARFdb6/.git/modules/empty-repo/modules/empty-repo --work-tree /tmp/tmp.pG92ARFdb6/empty-repo/empty-
repo -c core.quotepath=off ls-files /tmp/tmp.pG92ARFdb6/empty-repo2/empty-repo/README.md
fatal: /tmp/tmp.pG92ARFdb6/empty-repo2/empty-repo/README.md: '/tmp/tmp.pG92ARFdb6/empty-repo2/empty-repo/README.md' is outside repository at '/tmp/tmp.pG92ARFdb6/empty-repo/empty-repo'

 $ cd /tmp/tmp.pG92ARFdb6/empty-repo2/empty-repo/
 $ git --git-dir /tmp/tmp.pG92ARFdb6/.git/modules/empty-repo/modules/empty-repo --work-tree /tmp/tmp.pG92ARFdb6/empty-repo/empty-repo ls-files README.md
README.md

Seems to work - all inside Nvim terminal. It's hard for me to judge how risky it would be to allow for querying paths relative to CWD in Gitsigns.

I changed the original bash script to make it more reusable.