Go is a new language (while it was developed in public, release 1 was just months ago) so of course the library situation is less well defined than in older languages.
On the positive side, the standard libraries are very consistent, the good 3rd party libraries tend to follow the conventions of the standard libraries (lots of decisions made in the language and tooling make it easier to do things the Go way than to treat it like it is another language) and if you really need some large chunk of functionality that Go doesn't provide and you don't have the time or willingness to make a pure Go version, you can easily pull C libraries in via cgo.
On the positive side, the standard libraries are very consistent, the good 3rd party libraries tend to follow the conventions of the standard libraries (lots of decisions made in the language and tooling make it easier to do things the Go way than to treat it like it is another language) and if you really need some large chunk of functionality that Go doesn't provide and you don't have the time or willingness to make a pure Go version, you can easily pull C libraries in via cgo.