version: improve link type detection fall back

[shcheklein]

To reproduce:

dvc version outside of any DVC repo.

Output:

WARNING: Unable to detect supported link types, as cache directory '.dvc/cache' doesn't exist. It is usually auto-created by commands such as `dvc add/fetch/pull/run/import`, but you could create it manually to enable this check.

It should instead generate a regular output and either omit the link type completely or print some special value "link: (run inside repo)"

@shcheklein , I couldn't reproduce the issue with the following script:

mkdir /tmp/example
cd /tmp/example
python3.7 -m venv .venv
source .venv/bin/activate
pip install dvc
dvc version

@ptrcklv , could you provide a reproduction script?

[shcheklein]

@MrOutis me neither! And from the code perspective I don't see a bug. It might be I had a .dvc somewhere in the ~ (you know it happens from time to time when you do dvc init at the very top) - this is the only explanation that comes to my mind.

@shcheklein , @ptrcklv can we close this issue then? 🙂

[ptrcklv]

True, does not occur in arbitrary test dir. I could reproduce the error when I ran dvc version in my local dvc repo, i.e. in a code directory. Actually it is not a dvc repo but there is a .dvc folder, which fooled me, too.

👀 what about using Zsh @shcheklein , @ptrcklv? you can do cool things like the following:

any suggestions on how to leverage this? I didn't want to add dvc --version because it can take quite some time to compute (no bueno)

@shcheklein , @ptrcklv can you go to the referenced PR on spaceship-prompt and add your comments? (e.g. "this is not needed, please, close it immediately", "neat, but won't use", etc.)

[shcheklein]

@ptrcklv

Actually it is not a dvc repo but there is a .dvc folder, which fooled me, too.

Is that .dvc directory a leftover from some experiments or is a coincidence and you had it even before .dvc?

[shcheklein]

@MrOutis I think to the most part it's an UI ticket, we should just update the message to be more explicit:

"Unable to detect supported link types. You run this command inside DVC repo (.dvc exists) but it looks it has been just initialized as cache directory ("show here actual path to the cache dir from config") does not exist yet. It is usually auto-created by commands such as dvc add/fetch/pull/run/import, but you could create it manually to enable this check. "

It can be the second example for the Troubleshooting cc @jorgeorpinel and we can simplify a message and put a link to the command reference ... I even think if we need to introduce a short-cut similar to man.dvc.org - like error.dvc.org\<code> that redirects to the Troubleshooting section with a specific error.