add snap tests

[casperdcl]

• move snap build script to ./scripts
• Snap stable channel not updating #3152 make sure channel: stable pushes successfully (not just edge)
• test dvc
  • --version
  • version
  • get doesn't work due to unknown CI (travis) issue; will test in add snap tests dvc-test#8 instead.
• revert # TODO line in .travis.yml
• fixes add snap tests #2954
• (re) fix Snap stable channel not updating #3152

[casperdcl]

https://status.python.org/

PyPI Backends Unavailable
Investigating - We are currently investigating this issue.
Dec 14, 17:10 UTC

Looks like they've had issues for a couple of days though:

[casperdcl]

https://travis-ci.com/iterative/dvc/jobs/268243764#L2141

+dvc get https://github.com/iterative/dvc scripts/innosetup/dvc.ico
ERROR: failed to get 'scripts/innosetup/dvc.ico' from 'https://github.com/iterative/dvc' - URL 'https://github.com/iterative/dvc' is not a dvc repository.

@efiop not sure how to debug this - the command works on my machine

[efiop]

@casperdcl Let's start with full log first (add -v flag). But it is probably caused by gitpython not being able to clone from that url, not sure about specific reasons.

[casperdcl]

hm tried to re-run in case it was a connectivity issue. Also added -v:

dvc get -v https://github.com/iterative/dvc scripts/innosetup/dvc.ico
DEBUG: Removing '.E2pCP5rJPv8KEEHvaEUce9'
ERROR: failed to get 'scripts/innosetup/dvc.ico' from 'https://github.com/iterative/dvc' - URL 'https://github.com/iterative/dvc' is not a dvc repository.
------------------------------------------------------------
Traceback (most recent call last):
  File "/snap/dvc/x1/lib/python3.6/site-packages/dvc/repo/get.py", line 47, in get
    with external_repo(cache_dir=tmp_dir, url=url, rev=rev) as repo:
  File "/snap/dvc/x1/usr/lib/python3.6/contextlib.py", line 81, in __enter__
    return next(self.gen)
  File "/snap/dvc/x1/lib/python3.6/site-packages/dvc/external_repo.py", line 25, in external_repo
    path = _external_repo(url=url, rev=rev_lock or rev, cache_dir=cache_dir)
  File "/snap/dvc/x1/lib/python3.6/site-packages/dvc/external_repo.py", line 71, in _external_repo
    repo = Repo(new_path)
  File "/snap/dvc/x1/lib/python3.6/site-packages/dvc/repo/__init__.py", line 81, in __init__
    root_dir = self.find_root(root_dir)
  File "/snap/dvc/x1/lib/python3.6/site-packages/dvc/repo/__init__.py", line 149, in find_root
    raise NotDvcRepoError(root)
dvc.exceptions.NotDvcRepoError: you are not inside of a dvc repository (checked up to mount point /')
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
  File "/snap/dvc/x1/lib/python3.6/site-packages/dvc/command/get.py", line 23, in run
    rev=self.args.rev,
  File "/snap/dvc/x1/lib/python3.6/site-packages/dvc/repo/get.py", line 76, in get
    raise UrlNotDvcRepoError(url)
dvc.exceptions.UrlNotDvcRepoError: URL 'https://github.com/iterative/dvc' is not a dvc repository.
------------------------------------------------------------

[efiop]

@casperdcl Sorry, just noticed your comment. Probably connectivity issues in the container? Maybe it needs some special perms to access the network?

[efiop]

@casperdcl Was the issue resolved?

[casperdcl]

nope, just mistakenly deleted the branch

[casperdcl]

just rebased; will try to investigate. Do we have ssh debugging in travis @efiop?

[casperdcl]

well running the snap's built-in version of git works (dvc.git fetch --all completes successfully) so it doesn't seem to be a snap connectivity issue. Maybe missing dependencies for dvc get?

[casperdcl]

also the fact that dvc.git status works successfully implies that file system i/o isn't an issue either

[efiop]

just rebased; will try to investigate. Do we have ssh debugging in travis @efiop?

I'm pretty sure we don't. Or at least I'm not aware of it.

Try modifying find_root https://github.com/iterative/dvc/blob/master/dvc/repo/__init__.py#L132 to print listdirs when he walks them. Looks like it doesn't see .dvc for some reason, which might be because of a broken git clone, which could be broken because of gitpython and some weird env situation here.
These are just my thoughts, I haven't looked into this deep enough.

[efiop]

@casperdcl Looks good. Is this ready for merge?

EDIT: got a confirmation in PMs.