Cocoapods 'stuck at v.2.1'
The latest release(s) isn't showing in Cocoapods:

v2.2.0 only contains fixes specific to Swift Package Manager and Carthage, but it would be nice if @ceeK could push it to CocoaPods trunk to avoid confusion. (I’d be happy to help out as a co-owner of the pod.)
While the .podspec has been updated in 26572bf928e1c3f20cdbdcbdd1376e4fa9671b88, it has not been pushed to the CocoaPods repository.
In #56, I introduced a Solar-dev pod that you can use in the meantime as a workaround.
@1ec5 @ceeK would it be possible to update cocoapods with 3.0.1?
If you need v3.x, use the Solar-dev pod for now: https://github.com/ceeK/Solar#cocoapods