No metapack executable after a fresh installation

[roll]

$ pip install metapack
$ metapack
metapack: not found

[ericbusboom]

Ah, sorry, documentation error. The program name has been changed to mt with metapack being the subcommand mt pack.

[ericbusboom]

I updates the README, but the older documentation still needs to be changed.

[roll]

@ericbusboom
I've tried td but got this on a fresh virtualenv for Python 3.5.:

$ pip install metapack
$ mt
Traceback (most recent call last):
  File "/home/roll/projects/sandbox/.python/lib/python3.5/site-packages/pkg_resources/__init__.py", line 664, in _build_master
    ws.require(__requires__)
  File "/home/roll/projects/sandbox/.python/lib/python3.5/site-packages/pkg_resources/__init__.py", line 981, in require
    needed = self.resolve(parse_requirements(requirements))
  File "/home/roll/projects/sandbox/.python/lib/python3.5/site-packages/pkg_resources/__init__.py", line 872, in resolve
    raise VersionConflict(dist, req).with_context(dependent_req)
pkg_resources.ContextualVersionConflict: (six 1.11.0 (/home/roll/projects/sandbox/.python/lib/python3.5/site-packages), Requirement.parse('six~=1.10.0'), {'rowpipe'})

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/home/roll/projects/sandbox/.python/bin/mt", line 6, in <module>
    from pkg_resources import load_entry_point
  File "/home/roll/projects/sandbox/.python/lib/python3.5/site-packages/pkg_resources/__init__.py", line 3142, in <module>
    @_call_aside
  File "/home/roll/projects/sandbox/.python/lib/python3.5/site-packages/pkg_resources/__init__.py", line 3126, in _call_aside
    f(*args, **kwargs)
  File "/home/roll/projects/sandbox/.python/lib/python3.5/site-packages/pkg_resources/__init__.py", line 3155, in _initialize_master_working_set
    working_set = WorkingSet._build_master()
  File "/home/roll/projects/sandbox/.python/lib/python3.5/site-packages/pkg_resources/__init__.py", line 666, in _build_master
    return cls._build_from_requirements(__requires__)
  File "/home/roll/projects/sandbox/.python/lib/python3.5/site-packages/pkg_resources/__init__.py", line 679, in _build_from_requirements
    dists = ws.resolve(reqs, Environment())
  File "/home/roll/projects/sandbox/.python/lib/python3.5/site-packages/pkg_resources/__init__.py", line 872, in resolve
    raise VersionConflict(dist, req).with_context(dependent_req)
pkg_resources.ContextualVersionConflict: (six 1.11.0 (/home/roll/projects/sandbox/.python/lib/python3.5/site-packages), Requirement.parse('six~=1.10.0'), {'rowpipe'})

Not sure what's package have such a strong dependency version lock.

PS.
To do not create new issue on the http://metatab.org/:

• link to metatab spec is not working (blue button)
• link to data data package spec is not working (blue button)

[ericbusboom]

The package is fs, which has the dependency for six specified as:

"six~=1.10",

So, you have to manually re-install six:

$ pip uninstall -y six
$ pip install six==1.10.0

There a note about it buried in the README, but I'd really like to find a real fix. I'm almost ready to fork fs. Oddly, this wasn't an issue until I started using the entry points from pkg_resources, which is where the dependency is being checked. Maybe it's actually a bug in pkg_resources?

[roll]

@ericbusboom
I've proposed a PR to fs. It's probably just a bug because python libraries just can't use dependencies like this (if I correctly understand an used notation).

[roll]

I've downgraded the six version but I suppose I'm doing something wrong:

$ mt pack -c
CRITICAL: Failed to instantiate generator for class '<class 'rowgenerators.generator.csv.CsvSource'>', ref 'file:/home/roll/projects/sandbox/package/metadata.csv'

[ericbusboom]

Hmm... looks familiar. Let me investigate. That's probably a failure in the entry points for generators.

[ericbusboom]

BTW, adding '--exceptions' to the command line arguments gives you the full exception trace. In this case, it reveals that the error is because the metadata.csv template didn't get included in the package ( in the source, metatab/templates ) , probably because I screwed up the setup.py file and didn't change the MANIFEST. I've got a branch that I'm working on now which should fix this.

[willmcgugan]

Hello. That PR to fs shouldn't really change anything. The six~=1.10 should be equivalent to six>=1.10,<2.0 as I understand it.

What was the issue you are seeing?

[ericbusboom]

@willmcgugan The issue occurs entirely outside of fs, when the metatab code is trying to resolve entry_points. It looks like the problem is that pkg_resources, when checking dependencies on entry_points, doesn't understand the '~=' notation and rejects the specification. But, we haven't dug into the problem enough to be sure.

[roll]

@willmcgugan
My bad. I've missed that PyFilesystem/pyfilesystem2#79 has been resolved.

[willmcgugan]

Ah, you may need a more recent setuptools that supports ~=