[aleksi]

For a few things like system DNS resolver in net package (can be switched to the pure Go version with compile-time or run-time switch) and getting user's home directory in os/user package.

[sebcat]

To expand on this:

    $ cat foo.go 
    package main
    
    import (
     	"fmt"
    )
    
    func main() {
    	fmt.Println("Hello")
    }
    $ go build foo.go
    $ file foo
    foo: ELF 64-bit LSB executable, x86-64, version 1 (SYSV), statically linked, not stripped

compared to:

    $ cat bar.go
    package main
    
    import (
    	"os/user"
    	"fmt"
    )
    
    func main() {
    	u, err := user.Current()
    	fmt.Println(u, err)
    }
    $ go build bar.go
    $ file bar
    bar: ELF 64-bit LSB executable, x86-64, version 1 (SYSV), dynamically linked, interpreter /lib64/ld-linux-x86-64.so.2, not stripped

[ptman]

You can usually build fully static by doing

    CGO_ENABLED=0 go build

even when using os/user or net/

[sebcat]

At a computer with go1.4.2 freebsd/amd64 ATM (earlier was go1.8.1 linux/amd64 IIRC) and the above os/user example results in a dynamically linked ELF when built with CGO_ENABLED set to 0.