cmd/compile: 'duplicate symbol' error building some Go programs after commit 295307a

[siebenmann]

What version of Go are you using (go version)?

The error happens in go version devel +295307a Tue Mar 14 18:49:23 2017 +0000 linux/amd64 and not in the immediately previous commit go version devel +6917553. This commit is for issue #19361 'cmd/compile: Devirtualize calls when concrete type behind interface is statically known', so perhaps this bug report should go on to that issue.

What operating system and processor architecture are you using (go env)?

GOARCH="amd64"
GOHOSTARCH="amd64"
GOHOSTOS="linux"
GOOS="linux"

What did you do?

GOPATH=/tmp/test; export GOPATH
go get github.com/tsenart/vegeta
# github.com/tsenart/vegeta
2017/03/14 15:48:55 duplicate symbol github.com/tsenart/vegeta/lib.(*Results).Len (types 1 and 1) in main and /tmp/test/pkg/linux_amd64/github.com/tsenart/vegeta/lib.a(_go_.o)

What did you expect to see?

No compile error.

What did you see instead?

The compile error shown above.

[odeke-em]

I can reproduce your bug on OSX too

$ go get -u github.com/tsenart/vegeta
# github.com/tsenart/vegeta
2017/03/14 14:32:20 duplicate symbol github.com/tsenart/vegeta/lib.(*Results).Len (types 1 and 1) in main and /Users/emmanuelodeke/go/pkg/darwin_amd64/github.com/tsenart/vegeta/lib.a(_go_.o)
$ uname -a
Darwin Emmanuels-MacBook-Pro-2.local 15.6.0 Darwin Kernel Version 15.6.0: Mon Aug 29 20:21:34 PDT 2016; root:xnu-3248.60.11~1/RELEASE_X86_64 x86_64

/cc @dr2chase @philhofer

[gopherbot]

CL https://golang.org/cl/38179 mentions this issue.

[gopherbot]

CL https://golang.org/cl/38156 mentions this issue.