adding a minimal lgtm.yml file

[chapoton]

This will tell LGTM to use Python3 during its code analysis.

as suggested here:

​https://lgtm.com/help/lgtm/analysis-faqs#how-python-version-identified

[chapoton]

New commits:

​d6728ff

adding a .lgtm.yml file to specify the python version

[fbissey]

That looks interesting.

[chapoton]

The reports can be found here:

​https://lgtm.com/projects/g/sagemath/sage/?mode=list

but the problem is that it only runs when "master" branch is updated..

[embray]

I wonder if there is a setting to change the branch to track.

[chapoton]

the only way seems to be : change our main branch on github to be "develop"

[embray]

Replying to embray:

I wonder if there is a setting to change the branch to track.

ISTM that LGTM is reading from the GitHub mirror of our repo, so I just need to change its default branch to the develop branch. I don't *think* there will be any consequences to doing so, so I'll go ahead and do that.

[embray]

I'm looking at this site, and while many of the alerts look useful, a great many of the "errors" reported are due to supposedly incorrect arguments to a class's __init__, except their analysis is not clever enough to consider classes which have a metaclass with a custom __call__ (e.g. our ClasscallMetaclass which is used all over the place).

So perhaps while we're adding this file it might be helpful to globally exclude this and related errors as explained ​here. For example, from what I'm seeing in the errors, we want at least:

queries:
    - exclude: py/call/wrong-named-class-argument
    - exclude: py/call/wrong-number-class-arguments

Of course, we can also suppress alerts on individual lines, but these two are so pervasive it would not be practical. Suppressing them globally unfortunately could hide legitimate errors, though these errors are likely to be caught by tests in most cases.

[git]

Branch pushed to git repo; I updated commit sha1. New commits:

​84f4cd3

more stuff in lgtm.yml

[chapoton]

indeed. Done

[embray]

Heh, actually it turns out the actual majority of errors are of the class ​py/unsafe-cyclic-import. We should probably globally disable that one as well :)

[embray]

If you add that too, can you please also include in your commit message a link to this discussion so that it's clearer why it was added.

[git]

Branch pushed to git repo; I updated commit sha1. New commits:

​7b76a05

more stuff in lgtm.yml

[embray]

Turns out there was already a recent ​issue for false positives due to custom metaclass __call__s. I added some examples to it.

---

New commits:

​7b76a05

more stuff in lgtm.yml

[embray]

Replying to embray:

If you add that too, can you please also include in your commit message a link to this discussion so that it's clearer why it was added.

LGTM :)

Though please consider either squashing your commits and/or adding some more details or link to this ticket. "adding stuff to this file for no apparent reason"-type commit messages are not helpful :(

[git]

Branch pushed to git repo; I updated commit sha1 and set ticket back to needs_review. This was a forced push. New commits:

​f3640c2

adding a minimal .lgtm.yml file

[chapoton]

ok, better like that ?

[embray]

Thank you!