What do three dots "./..." mean in Go command line invocations?

If you run Golang tests on Travis CI, it will download all of your dependencies with three dots:

go get -d -v ./... && go build -v ./...

What does ./... indicate or expand to there? I've done some research but it doesn't seem to be a Unix convention.

From the command go help packages:


An import path is a pattern if it includes one or more "..." wildcards,
each of which can match any string, including the empty string and
strings containing slashes. Such a pattern expands to all package
directories found in the GOPATH trees with names matching the
patterns. As a special case, x/... matches x as well as x's subdirectories.
For example, net/... expands to net and packages in its subdirectories.

Stack Overflow Q#28031603, score: 196