dvc list: Error on empty directory.

[karajan1001]

Bug Report

Got error message on an empty directory, shouldn't it show nothing? like ls command.

Description

Error when list a empty path, strange behavior.
Might relate to

dvc/dvc/repo/ls.py

Lines 40 to 41 in daf0745

	if path and not ret:
	raise PathMissingError(path, repo, dvc_only=dvc_only)

Reproduce

1. git init
2. dvc init
3. mkdir empty
4. dvc list . empty

Expected

Show nothing like ls command

Environment information

DVC version: 2.0.17+7e4851

Platform: Python 3.8.8 on macOS-10.16-x86_64-i386-64bit
Supports: All remotes
Cache types: https://error.dvc.org/no-dvc-cache
Caches: local
Remotes: None
Workspace directory: apfs on /dev/disk3s1s1
Repo: dvc, git

Output of dvc doctor:

$ dvc doctor

Additional Information (if any):

[karajan1001]

We have already had a test about this.

dvc/tests/func/test_ls.py

Lines 167 to 173 in 68897aa

	def test_ls_repo_with_path_dir_dvc_only_empty(tmp_dir, dvc, scm):
	tmp_dir.scm_gen(FS_STRUCTURE, commit="init")
	tmp_dir.dvc_gen(DVC_STRUCTURE, commit="dvc")
	tmp_dir.scm_gen({"folder/.keep": "content"}, commit="add .keep")
	with pytest.raises(PathMissingError):
	Repo.ls(os.fspath(tmp_dir), path="folder", dvc_only=True)

and it was introduced from #3246 at the beginning of dvc list command.

[evanrittenhouse]

@karajan1001 is this still open? New to open source, but would love to take a stab at it

[karajan1001]

open

Sorry, we had already had a PR for it (#6120) but was blocked by some refactoring. So maybe it is better to start with some other issues with good first issue.