Preparing for Go 1.5

[Michael Hudson-Doyle]

An update.

On 31 July 2015 at 09:39, Michael Hudson-Doyle
<michael.hudson at canonical.com> wrote:
> Hi everyone,
>
> Go 1.5 will be released soon (target is actually August 1 but that's
> not going to be hit). I've been doing some testing to see what will
> break when we upload it.

Still no rc, so probably no 1.5 release for at least a week, maybe two.

> I have a PPA at
> https://launchpad.net/~mwhudson/+archive/ubuntu/go1.5-rebuild-tests/+packages
> which contains a Go 1.5 snapshot package and all things that
> build-depend on golang-go.

I now have another PPA at
https://launchpad.net/~mwhudson/+archive/ubuntu/go1.5-arch-tests/+packages
that contains an golang-go snapshot which ...

> As a bit of background, there is a hack in the Ubuntu packaging that
> means that packages are magically built with gccgo on arm64, ppc64le
> and powerpc ("gccgo platforms"). Go 1.5 actually supports arm64 and
> ppc64le but I'm not testing that yet.

... does build 'real go' for arm64 and ppc64el.

> There are a few packages that fail to build on gccgo platforms but
> build fine with Go 1.5: account-polld, ciborium, golang-goyaml,
> golang-log4go. As the situation is not changed by uploading a Go 1.5
> snapshot, this doesn't require action.

golang-goyaml and golang-log4go now build on arm64 and ppc64el.
account-polld does not and ciborium builds on arm64 only. As this is a
net improvement, I don't see any reason here to not enable 'real go'
for arm64 and ppc64el. There is one package that builds with gccgo but
not golang-go on ppc64el: lxd. We can fix that by tweaking the
packaging to depend on gccgo and not golang-go on ppc64el (the problem
is known and I'll fix it for Go 1.6).

> Some binaries have moved from golang-go.tools to golang-go in this
> release (cover, vet). This means that the golang-go 1.5 package needs
> to Breaks/Replaces with the older go tools and we should upload a new
> go.tools at the same time as the golang-go package. There are two
> packages that build depend on go.tools and so failed in my builds
> (aptly and unity-scope-snappy); these pass with the updated go.tools
> but as they only build depend on go.tools to get access to cover, the
> build-dep can be dropped once 1.5 has been uploaded. The newer
> go.tools package depends on a newer dh-golang -- I haven't done a full
> rebuild test with the newer tools/dh-golang packages yet.

My new ppa gets this stuff right -- there is an updated go tools
package that works with Go 1.5 and the golang-go package
breaks/replaces old go tools.

Rebuilding everything with the new dh-golang threw up one new failure
in ubuntu-snappy
(https://bugs.launchpad.net/ubuntu/+source/ubuntu-snappy/+bug/1481120).

> There are a few packages that ftbfs in the archive already:
> golang-doozer, golang-github-glacjay-goini, golang-gocheck, and
> ubuntu-push. Of these only golang-gocheck has non-trivial rdepends and
> the fix for these is to move upstream to golang-check.v1 (I haven't
> looked into pushing upstreams into doing this yet). ubuntu-push is
> seeded so probably should be fixed ASAP by upstream
> (https://bugs.launchpad.net/ubuntu-push/+bug/1478741) but that's not
> directly relevant to the 1.5 transition.

ubuntu-push has been fixed to build with Go 1.4 now, but still fails
with Go 1.5.

> There are two packages that have been fixed to work with Go 1.5
> upstream but the fixes are not yet packaged in Debian:
> golang-golang-x-net-dev and golang-x-text. We should wait for these to
> be packaged before uploading Go 1.5. The upstream version of
> golang-x-text works with Go 1.5 but not Go 1.4 (reported as
> https://github.com/golang/go/issues/11927) so perhaps that should be
> uploaded at the same time.

The change in Go 1.5 that caused the golang-golang-x-net-dev failure
was reverted so that builds now. No change in the golang-x-text
situation.

> There are four packages that fail with Go 1.5 and have not been fixed
> upstream: golang-github-jacobsa-ogletest, golang-protobuf-extensions,
> ubuntu-push (over and above the failures with 1.4), and ubuntu-snappy.
> I've filed bugs for all of these:
>
>  * https://github.com/jacobsa/ogletest/issues/28
>  * https://github.com/matttproud/golang_protobuf_extensions/issues/9
>  * https://bugs.launchpad.net/ubuntu-push/+bug/1478742
>  * https://bugs.launchpad.net/snappy/+bug/1478736
>
> The first two have few rdeps and IMO can be left alone for now. The
> latter two are seeded and we should wait for fixes before uploading
> 1.5.

The change in Go 1.5 that caused the snappy failure was reverted. But
it still doesn't build because of the dh-golang thing.

A new failure caused by changes in Go 1.5 since the last snapshot is
docker.io (https://github.com/docker/docker/issues/15279).

A handful of packages that have appeared in the archive since my last
rebuild fail with Go 1.5: prometheus-pushgateway, prometheus,
golang-github-armon-go-metrics, golang-prometheus-client. I'll file
upstream bugs for these soon.

libguestfs now fails to build, but I don't think that's Go's fault.

> One package has a failure on armhf that I don't understand:
> golang-ginkgo (I think possibly it's just running out of RAM). As this
> only has one rdep (leveldb) that builds fine, I'm proposing to leave
> this alone.

golang-ginkgo succeeded on armhf this time but failed on arm64 and
ppc64el. I don't know what's going on there.

golang-gogoprotobuf -- which has been updated since my previous test
-- failed this time on amd64 (but not other platforms) when the build
ran out of RAM.

I think the status is not really much better or worse than before,
although the docker and snappy failures need to be fixed before we
upload Go 1.5.

I see no reason from this not to build golang-go on arm64 and ppc64el.

Cheers,
mwh

> Comments welcome!
>
> Cheers,
> mwh