Please consider adding PyPy Trove classifiers, because apparently black works fine! At least on the recent PyPy (I tested PyPy3.6 v7.0 on macOS). I used version 18.9b0 of black. See https://pypy.org/download.html

#4478 included some initial support for the new ConstBlock expression kind variant, but there's opportunities to enhance and improve the formatting.

The relevant section of the codebase can be found in formatting/expr.rs
https://github.com/rust-lang/rustfmt/blob/cbe01e47024c852e2ed852671e76f7929c4bab91/src/formatting/expr.rs#L127-L129

There are 3 core activities to completing this issue:

When I try to beautify the i get the following problem
TypeError: Cannot read property 'on' of undefined

I just installed beautify and uncrustify

https://gist.github.com/ODCA117/917affd6b11437517535a45350379820

We need to update our README.md file before the 1.0 release.