ImportError in every `dvc command` after `pip install -e` in develop environment

[karajan1001]

Bug Report

ImportError: cannot import name '__version__' from '_version' (/Users/gao/Code/dvc/dvc/_version.py)

After every dvc command didn't affect the command running but quite anonying.

Description

Meet this error message after every command.

Traceback (most recent call last):
  File "/Users/gao/Code/dvc/dvc/__main__.py", line 7, in <module>
    sys.exit(main(sys.argv[1:]))
  File "/Users/gao/Code/dvc/dvc/main.py", line 97, in main
    if analytics.is_enabled():
  File "/Users/gao/Code/dvc/dvc/analytics.py", line 50, in is_enabled
    Config(validate=False).get("core", {}).get("analytics", "true")
  File "/Users/gao/Code/dvc/dvc/config.py", line 107, in __init__
    self.load(validate=validate, config=config)
  File "/Users/gao/Code/dvc/dvc/config.py", line 153, in load
    conf = self.load_config_to_level()
  File "/Users/gao/Code/dvc/dvc/config.py", line 278, in load_config_to_level
    merge(merged_conf, self.load_one(merge_level))
  File "/Users/gao/Code/dvc/dvc/config.py", line 202, in load_one
    conf = self._load_config(level)
  File "/Users/gao/Code/dvc/dvc/config.py", line 174, in _load_config
    from configobj import ConfigObj
  File "/Users/gao/anaconda3/envs/dvc/lib/python3.8/site-packages/configobj.py", line 23, in <module>
    from _version import __version__
ImportError: cannot import name '__version__' from '_version' (/Users/gao/Code/dvc/dvc/_version.py)

Reproduce

1. git clone git@github.com:iterative/dvc.git
2. cd dvc
3. pip3 install -e ".[all,tests]"
4. dvc doctor.

Expected

No error message

Environment information

Output of dvc doctor:

$ dvc doctor
DVC version: 2.8.2.dev35+geb0b4ce6
---------------------------------
Platform: Python 3.8.8 on macOS-10.16-x86_64-i386-64bit
Supports:
	azure (adlfs = 2021.9.1, knack = 0.8.0, azure-identity = 1.5.0),
	gdrive (pydrive2 = 1.9.4),
	gs (gcsfs = 2021.10.1),
	hdfs (fsspec = 2021.10.1, pyarrow = 3.0.0),
	webhdfs (fsspec = 2021.10.1),
	http (aiohttp = 3.7.4.post0, aiohttp-retry = 2.4.5),
	https (aiohttp = 3.7.4.post0, aiohttp-retry = 2.4.5),
	s3 (s3fs = 2021.10.1, boto3 = 1.17.106),
	ssh (sshfs = 2021.9.0),
	oss (ossfs = 2021.8.0),
	webdav (webdav4 = 0.9.3),
	webdavs (webdav4 = 0.9.3)
Cache types: <https://error.dvc.org/no-dvc-cache>
Caches: local
Remotes: oss, https, s3
Workspace directory: apfs on /dev/disk3s1s1
Repo: dvc, git

Additional Information (if any):

Error go out from configobj. It wants to read the contents from https://github.com/DiffSK/configobj/blob/master/src/configobj/_version.py but this file did not install properly.

And, as there is a _version.py generated automatically after pip install -e in our dvc repo. configobj wrongly reads it.

[skshetry]

The issue with _version is due to configobj.

Instead of importing from .version, it's importing from _version which is conflicting:
https://github.com/DiffSK/configobj/blob/9d2aab01c77dce600b296ba9da1163cc0bbc14e0/configobj.py#L23

This has been fixed in it's master, but it hasn't had a release for 6 years now.

[efiop]

@skshetry Does this affect users? Or just developers in -e mode? Anything we could do about it?

[daavoo]

But when was the bug introduced in DVC? I have been only noticed this the past few days.

[skshetry]

This also affects the users, as that's where we store version information. Using _version.py is the recommended practice (pypa/setuptools-scm#575). The workaround is to name the file anything other than _version. Perhaps __version__.py?

[efiop]

@daavoo It was introduced in #6775, we didn't release since then (specifically to catch such bugs).

@skshetry Thanks for the research! Could use _dvcversion.py or something so there is absolutely no chance of this colliding with anything else. But as long as it is reasonably unique - we should be fine 🙂