We’ve written a blog post summarizing the changes in this patch release: Crystal 1.6.1 released! - The Crystal Programming Language . While we have tested it against several known and sizeable projects, that doesn’t preclude the existence of regressions. If you find an issue, please check the issue tracker and file a bug: it will be fixed in the following patch version.
The full changelog is here: Release 1.6.1 · crystal-lang/crystal · GitHub .
It is already available on the supported platforms, check the install page for details. That includes docker images 
, snapcraft, .deb and .rpm packages, and the brew formula 
.
Happy Crystallizing!