building containers for go is broken

[tkellen]

Hi,

I'm just getting started with bazel and I'm hitting an issue building a very simple go container.

I have prepared a minimal reproduction here:
https://github.com/tkellen/bazel-test

...I would expect bazel run container to work but it does not. Have I missed something obvious?

I'm going to dig in now and see if I can fix the problem myself but I wanted to post this as a sanity check before I go down a rabbit hole I don't need to :)

Thanks in advance if you can help!

[mattmoor]

You want binary = ":helloworld" not embed

[tkellen]

Thanks @mattmoor! I tested that (and just pushed a commit updating the test repo) but I am seeing the same behavior.

[mattmoor]

Hmm, can you include the output when you run this?

One other thing to try would be to use pure = "on" on your go_binary target.

[tkellen]

Yup!

~/sources/go/src/github.com/tkellen/bazel-test master*
❯ bazel run container
INFO: Analysed target //:container (30 packages loaded).
INFO: Found 1 target...
Target //:container up-to-date:
  bazel-bin/container-layer.tar
INFO: Elapsed time: 44.962s, Critical Path: 5.04s
INFO: Build completed successfully, 11 total actions

INFO: Running command line: bazel-bin/container
Loaded image ID: sha256:404677e3f13437d7a3b6cc7a6fdb583ff9b77a5245c2f661aba249f2228776a7
Tagging 404677e3f13437d7a3b6cc7a6fdb583ff9b77a5245c2f661aba249f2228776a7 as bazel:container
standard_init_linux.go:195: exec user process caused "exec format error"
ERROR: Non-zero return code '1' from command: Process exited with status 1

...trying the pure setting now.

[tkellen]

I think this may be related to bazel-contrib/rules_go#1112 but I'm really not sure.

[mattmoor]

Yeah, I think pure = "on" is the right workaround for that. We've been seeing Go starting to link libstdc++ without pure go enabled, so we need to switch to the cc base image for go.

[tkellen]

Hmmm. No dice. Same output.

[mattmoor]

Can you push what you tried?

[tkellen]

Done.

[mattmoor]

Are you by chance on Windows / Mac?

If so, the problem is likely that you aren't cross compiling.

You can try adding this flag to your run command: --platforms=@io_bazel_rules_go//go/toolchain:linux_amd64.

If that works, you can put a .bazelrc file in the root of your repo with:

run --platforms=@io_bazel_rules_go//go/toolchain:linux_amd64

[mattmoor]

FYI this needs Bazel 0.10 to work, there was a bug in 0.9 :(

[tkellen]

Sorry, I should have shared that from the get go (my OS/Bazel version)

~/sources/go/src/github.com/tkellen/rules_docker master*
❯ bazel version
Build label: 0.10.0
Build target: bazel-out/darwin-opt/bin/src/main/java/com/google/devtools/build/lib/bazel/BazelServer_deploy.jar
Build time: Thu Nov 9 05:23:23 +50056 (1517474669003)
Build timestamp: 1517474669003
Build timestamp as int: 1517474669003

~/sources/go/src/github.com/tkellen/rules_docker master*
❯ uname -a
Darwin Tylers-MacBook-Pro.local 16.7.0 Darwin Kernel Version 16.7.0: Thu Jun 15 17:36:27 PDT 2017; root:xnu-3789.70.16~2/RELEASE_X86_64 x86_64

[mattmoor]

Does that flag fix things?

[tkellen]

Cross compiling worked. I assumed the build was running in a container with the right architecture. That's obviously wrong. Can I specify that somewhere in my BUILD file so this flag isn't needed?