FWIW I just tried it again after running git clean -xf and saw the same issue (although it only took 94.4s to fail that time).

I'm wondering why the linux longtest builder isn't seeing this. cmd/go is currently failing there, but not because of these tests: https://build.golang.org/log/6bad8944b0b76092ef2874ca932c643ccd63ec9e

I ran both locally, and they succeed. The second one is skipped because I don't have gccgo installed, though. Perhaps the first one isn't testing anything either.

/cc @ianlancetaylor

I can also reproduce the issue on current Go tip (08ab820).

@rogpeppe Which version of gccgo do you have installed?

I can't recreate this myself using tip gccgo. The error cannot find package "runtime" in any of suggests that the function isStandardPackage in go/build/gc.go has returned false for "runtime", although of course "runtime" is a standard package. What is the output of:

• gccgo -print-search-dirs
• gccgo -dumpversion
• gccgo -dumpmachine

?

Somewhere in your gccgo installation there should be a file runtime.gox, possibly two such files if you have both 32-bit and 64-bit libraries installed. What are the full paths of those files?

After some investigation, it seems that this is happening because I have an old gccgo binary installed in /usr/bin. If I run go test with a path that doesn't include gccgo, the test passes. Is it right that the go tests should be invoking an arbitrary binary outside of the go installation?

Maybe these tests should be skipped if the gccgo version is too old. This is already done with other third-party programs such as gdb.

It's helpful to have some tests of -compiler=gccgo, and how can we do it other than by running those tests if gccgo is on PATH? There are other tests that run system programs, such as gdb and nm.

What version of gccgo do you have installed?

@ianlancetaylor You should be able to reproduce the issue by running these commands:

docker run --rm -i -t ubuntu:16.04 bash
export DEBIAN_FRONTEND=noninteractive
adduser --disabled-password --gecos "" ubuntu
apt-get -y update < /dev/null
apt-get -y install git gcc curl gccgo < /dev/null
su ubuntu
cd /tmp
curl -sL https://dl.google.com/go/go1.11beta2.linux-amd64.tar.gz | tar -zx
cp -rp go go1.11beta2
export PATH=/tmp/go1.11beta2/bin:$PATH
go version
cd go/src/
./all.bash

Here are the results of running your suggested gccgo commands:

$ gccgo -print-search-dirs
install: /usr/lib/gcc/x86_64-linux-gnu/6/
programs: =/usr/lib/gcc/x86_64-linux-gnu/6/:/usr/lib/gcc/x86_64-linux-gnu/6/:/usr/lib/gcc/x86_64-linux-gnu/:/usr/lib/gcc/x86_64-linux-gnu/6/:/usr/lib/gcc/x86_64-linux-gnu/:/usr/lib/gcc/x86_64-linux-gnu/6/../../../../x86_64-linux-gnu/bin/x86_64-linux-gnu/6/:/usr/lib/gcc/x86_64-linux-gnu/6/../../../../x86_64-linux-gnu/bin/x86_64-linux-gnu/:/usr/lib/gcc/x86_64-linux-gnu/6/../../../../x86_64-linux-gnu/bin/
libraries: =/usr/lib/gcc/x86_64-linux-gnu/6/:/usr/lib/gcc/x86_64-linux-gnu/6/../../../../x86_64-linux-gnu/lib/x86_64-linux-gnu/6/:/usr/lib/gcc/x86_64-linux-gnu/6/../../../../x86_64-linux-gnu/lib/x86_64-linux-gnu/:/usr/lib/gcc/x86_64-linux-gnu/6/../../../../x86_64-linux-gnu/lib/../lib/:/usr/lib/gcc/x86_64-linux-gnu/6/../../../x86_64-linux-gnu/6/:/usr/lib/gcc/x86_64-linux-gnu/6/../../../x86_64-linux-gnu/:/usr/lib/gcc/x86_64-linux-gnu/6/../../../../lib/:/lib/x86_64-linux-gnu/6/:/lib/x86_64-linux-gnu/:/lib/../lib/:/usr/lib/x86_64-linux-gnu/6/:/usr/lib/x86_64-linux-gnu/:/usr/lib/../lib/:/usr/lib/gcc/x86_64-linux-gnu/6/../../../../x86_64-linux-gnu/lib/:/usr/lib/gcc/x86_64-linux-gnu/6/../../../:/lib/:/usr/lib/
$ gccgo -dumpversion
6.0.0
$ gccgo -dumpmachine
x86_64-linux-gnu

I'm not sure exactly what you mean by "in my gccgo installation". dpkg -L prints this, which doesn't seem to include a .gox file:

% dpkg -L gccgo
/.
/usr
/usr/bin
/usr/share
/usr/share/doc
/usr/share/man
/usr/share/man/man1
/usr/bin/gccgo
/usr/bin/x86_64-linux-gnu-gccgo
/usr/share/doc/gccgo
/usr/share/man/man1/x86_64-linux-gnu-gccgo.1.gz
/usr/share/man/man1/gccgo.1.gz

Credit to @myitcv for the initial version of the docker commands above BTW.

If gccgo works at all, then there must be a runtime.gox file and, for that matter, a libgo.a or libgo.so file, somewhere.

But perhaps gccgo doesn't work at all. Does it?

No, it doesn't seem to work at all. I must have done apt-get install gccgo it but never actually tried to use it. I guess the answer to the issue is "don't install gccgo with apt" then.

With the docker script you provided, gccgo does work, but the go tool does not. The problem is that gccgo is looking in a subdirectory go/6 but gccgo -dumpversion prints 6.0.0. The search path used by the go tool is looking for go/6.0.0 but only go/6 exists. I don't understand why this is; it may possibly be a Ubuntu- or Debian- local patch to GCC. I've asked an Ubuntu GCC maintainer for more information.

Ubuntu bug filed at https://bugs.launchpad.net/ubuntu/+source/gcc-6/+bug/1783930 .

According to that bug this works with gccgo versions 7 and 8.

Since there doesn't seem to be anything to fix in the Go project, closing this issue.