tests/test-empty.t

error: make HintException a mix-in class not derived from BaseException (API)

HintException is unrelated to the hierarchy of errors. It is an implementation
detail whether a class inherits from HintException or not, a sort of "private
inheritance" in C++.

New Hint isn't an exception class, which prevents catching error by its type:

    try:
        dosomething()
    except error.Hint:
        pass

Unfortunately, this passes on PyPy 5.3.1, but not on Python 2, and raises more
detailed TypeError on Python 3.

Create an empty repo:

  $ hg init a
  $ cd a

Try some commands:

  $ hg log
  $ hg grep wah
  [1]
  $ hg manifest
  $ hg verify
  checking changesets
  checking manifests
  crosschecking files in changesets and manifests
  checking files
  0 files, 0 changesets, 0 total revisions

Check the basic files created:

  $ ls .hg
  00changelog.i
  requires
  store

Should be empty:

  $ ls .hg/store

Poke at a clone:

  $ cd ..
  $ hg clone a b
  updating to branch default
  0 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cd b
  $ hg verify
  checking changesets
  checking manifests
  crosschecking files in changesets and manifests
  checking files
  0 files, 0 changesets, 0 total revisions
  $ ls .hg
  00changelog.i
  hgrc
  requires
  store

Should be empty:

  $ ls .hg/store

  $ cd ..