One minor detail of the default formatting of Go source code has changed. When formatting expression lists with inline comments, the comments were aligned according to a heuristic. However, in some cases the alignment would be split up too easily, or introduce too much whitespace. The heuristic has been changed to behave better for human-written code.
Also note that:
[...] these kinds of minor updates to gofmt are expected from time to time. In general, systems that need consistent formatting of Go source code should use a specific version of the gofmt binary.