can't go build with -race

[John Lenton]

john@fogey:/tmp$ cat example.go
package main

func main() {
 println("hi")
}
john@fogey:/tmp$ go build -o example example.go
john@fogey:/tmp$ go build -race -o example example.go
# command-line-arguments
runtime.raceinit: __tsan_init: not defined
runtime.raceinit: __tsan_map_shadow: not defined
runtime.racefini: __tsan_fini: not defined
runtime.racemapshadow: __tsan_map_shadow: not defined
runtime.racemalloc: __tsan_malloc: not defined
runtime.racegostart: __tsan_go_start: not defined
runtime.racegoend: __tsan_go_end: not defined
runtime.raceacquireg: __tsan_acquire: not defined
runtime.racereleaseg: __tsan_release: not defined
runtime.racereleasemergeg: __tsan_release_merge: not defined
runtime.racefingo: __tsan_finalizer_goroutine: not defined
runtime.raceread: __tsan_read: not defined
runtime.racereadpc: __tsan_read_pc: not defined
runtime.racewrite: __tsan_write: not defined
runtime.racewritepc: __tsan_write_pc: not defined
runtime.racereadrangepc1: __tsan_read_range: not defined
runtime.racewriterangepc1: __tsan_write_range: not defined
runtime.racefuncenter: __tsan_func_enter: not defined
runtime.racefuncexit: __tsan_func_exit: not defined
runtime.raceinit: undefined: __tsan_init
runtime.raceinit: undefined: __tsan_map_shadow
/usr/lib/go/pkg/tool/linux_amd64/link: too many errors

ProblemType: Bug
DistroRelease: Ubuntu 15.10
Package: golang-go 2:1.5-0ubuntu1
ProcVersionSignature: Ubuntu 4.2.0-10.11-generic 4.2.0
Uname: Linux 4.2.0-10-generic x86_64
ApportVersion: 2.18.1-0ubuntu1
Architecture: amd64
Date: Wed Sep 16 17:56:02 2015
InstallationDate: Installed on 2014-04-27 (506 days ago)
InstallationMedia: Ubuntu 14.04 LTS "Trusty Tahr" - Release amd64 (20140417)
SourcePackage: golang
SystemImageInfo: Error: command ['system-image-cli', '-i'] failed with exit code 2:
UpgradeStatus: Upgraded to wily on 2015-06-18 (89 days ago)