UI: output glitches

[Suor]

• dvc version has an empty line in the end if psutil is not installed (fixed in ui: fix extra newline in dvc version #3006)

• dvc init doesn't have a message about something is done,
  there is an empty line an then "You can now commit the changes to git"

• analytics prints errors after dvc exit if there is a network issue

• dvc version

  WARNING: ... but you could create it manually to enable this check

  ... can create ...

• dvc add pbar is named "Add", we do big efforts to show filenames when it's not really needed, like individual pushed files, but don't show filename in dvc add filename for single file
  We shouldn't show this pbar at all probably, esp. for small files.

• dvc add pbar doesn't disappear

• dvc move 1.csv 2.csv dup messages:

  Output '2.csv' didn't change. Skipping saving.
  Output '2.csv' didn't change. Skipping saving.
  ...

  Also, why do even need to say it's not changed? we are moving things here.

• dvc move on command out suggest moving by hand and editing stage file, should also metion about updating .gitignore

• dvc repros

  WARNING: Output 'foo' of 'foo.dvc' changed because it is 'modified'

  Looks idiotic and slightly confusing. "changed" and "modified" are synonyms, and why the ''s? This is "Hello a [stupid] robot is talking to you" approach to messages I'd like to get rid of.

• dvc repro not all changed deps are listed because of short-curcuiting:

  WARNING: Dependency 'foo' of 'foobar.dvc' changed because it is 'modified'.
  WARNING: Stage 'foobar.dvc' changed.
  Running command:

  Both foo and bar were changed, but we don't say it. Generally short-curcuiting should not affect UI.

Common source of many of these is printing at low-level where not all the context is available. So I suggest:

• stop printing anything in predicate methods
• print in action methods mostly

[dmpetrov]

@Suor thank you! It is a good one.

It might be related to #2565, #2979

[dberenbaum]

@skshetry Any sense of how many of these are still applicable?

[efiop]

closing as stale