rdoc and json are incompatible

[isuruf]

rdoc needs json ~> 1.4 (>=1.4, < 2.0) and nmatrix requires >= 2.0.1.

[translunar]

I believe I just put in ~> 2.0.1 because that's the one I got working at the time. Do you want to see what happens in your PR if you change it to 1.4?

[isuruf]

I just did, and it fails to install json 1.8.3. json needs to be updated to 2.0.1 to build with the latest ruby version. So, I guess this is an issue with rdoc

[isuruf]

Problem is that with ruby 2.4.0-dev, this is checked strictly. Earlier when ruby 2.0.1 was installed it was okay even if rdoc needed < 2.0. Now it is enforced and therefore fails.

[translunar]

Is this the problem?

ruby/json#303

It looks like we can just drop the json requirement altogether, yes?

[isuruf]

Yes, it is. Dropping the json requirement won't help, since rdoc has json as a requirement.

[isuruf]

Dropping the requirement will help ruby versions < 2.4

[translunar]

Looks like we need RDoc 5.

https://github.com/rdoc/rdoc/pull/412

[translunar]

Possibly related to #606?