cmd/compile: internal compiler error: Type.Elem UNSAFEPTR

[Saxon1]

Please answer these questions before submitting your issue. Thanks!

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

Version 1.10
doesn't happen on 1.9

Does this issue reproduce with the latest release?

I'm on the latest release.

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

GOARCH="amd64"
GOBIN=""
GOCACHE="/home/saxon/.cache/go-build"
GOEXE=""
GOHOSTARCH="amd64"
GOHOSTOS="linux"
GOOS="linux"
GOPATH="/home/saxon/go"
GORACE=""
GOROOT="/usr/lib/go-1.10"
GOTMPDIR=""
GOTOOLDIR="/usr/lib/go-1.10/pkg/tool/linux_amd64"
GCCGO="gccgo"
CC="gcc"
CXX="g++"
CGO_ENABLED="1"
CGO_CFLAGS="-g -O2"
CGO_CPPFLAGS=""
CGO_CXXFLAGS="-g -O2"
CGO_FFLAGS="-g -O2"
CGO_LDFLAGS="-g -O2"
PKG_CONFIG="pkg-config"
GOGCCFLAGS="-fPIC -m64 -pthread -fmessage-length=0 -fdebug-prefix-map=/tmp/go-build007043969=/tmp/go-build -gno-record-gcc-switches"

What did you do?

Tried 'go build' in av/rtmp on the repo: https://bitbucket.org/ausocean/av/src on the branch librtmpPorting.

What did you expect to see?

a clean build

What did you see instead?

bitbucket.org/ausocean/av/rtmp

:1:0: internal compiler error: Type.Elem UNSAFEPTR

Please file a bug report including a short program that triggers the error.
https://golang.org/issue/new

[Saxon1]

Note: I don't see this on go1.9

[ianlancetaylor]

I checked out https://bitbucket.org/ausocean/av, and ran git checkout librtmpPorting, but there is no src directory there. Can you give precise directions for reproducing the problem starting from scratch? Thanks.

[FiloSottile]

/cc @randall77 @josharian

@gopherbot please open a backport issue as this might be a 1.10 regression.

[gopherbot]

Backport issue(s) opened: #26402 (for 1.10).

Remember to create the cherry-pick CL(s) as soon as the patch is submitted to master, according to https://golang.org/wiki/MinorReleases.

[josharian]

@FiloSottile in the future, can we wait on backport setup until we can reproduce?

[ALTree]

I looked into this.

It seems like you hardcoded in a few places that the librtmp you are using with cgo can be found in /usr/local/lib. In fact, when I try to build the c dependencies of your project using make, it instructs me to run sudo make install-deps, which I have no intention to do.

Please provide a reproducer that can be compiled without the requirement of running a make command from root, if possible.

[ALTree]

I'll amend the comment I wrote above since it sounds unnecessarily harsh.

What I wanted to say is that, in general, Go contributors and the Go Devs will be able to help much quicker if the reproducer attached to a bug is easy to build. In this case I downloaded your repository, looked into it, and I found out that building it -apparently- requires to run a make command from root, to move headers you depend on into a specific system folder. Since running arbitrary commands from root is something that may have harmful consequences, anyone investigating your report may be unwilling to do that, and this will slow down the investigation. For this reason, we usually ask the reporter to try to make the reproducer as small, simple, and easy to build as possible.

[Saxon1]

I ended up committing past the problem. I'm going to rebase and create a new branch. I'll also provide instructions for building the C stuff in the program dir rather than in /usr/local. And apologies for making it more difficult to investigate. I'm quite a busy boy currently - once I went back to go1.9 and got it working, I nearly forgot about the issue.