It seems that sum.golang.org doesn't like this package right now. The last one I can actually pull is v0.4.0
Unsure whether this is a bug with sum.golang.org or not.
Thanks to @sgmitchell, this problem should be fixed already on master. I will create the 0.5.2 release just as a "shadow" for the 0.5.1 to allow you to vendor this pkg.
Can't go get -u github.com/mszostok/codeowners-validator as of v0.5.0
Directly hitting https://sum.golang.org/lookup/github.com/mszostok/codeowners-validator@v0.5.1
It seems that sum.golang.org doesn't like this package right now. The last one I can actually pull is v0.4.0 Unsure whether this is a bug with sum.golang.org or not.