move to per-Go-major version coinstallable packages

[Michael Hudson-Doyle]

To make maintenance of Go easier in the future, we've decided to allow major versions of Go to be co-installed (like gcc-4.9, gcc-5, etc). The plan goes something like this:

 1) convert existing golang source package to golang-1.6 source package, removing version independent things like the man pages and management of /usr/bin/go, changed to install to version dependent paths (/usr/lib/go-1.6 etc)
 2) create a golang-defaults package that contains this version independent stuff and links /usr/bin/go to the appropriate version
 3) update gccgo-5 and gccgo-6 packages to stop providing an alternative for 'go'.

The motivation for this is to allow us to upload pre-release versions of Go without making them the default, to provide a PPA that contains newer versions of Go for Xenial more smoothly and, if necessary, to allow us to upload newer versions to Go to xenial-updates (like #1536882 is doing for trusty) without having to conflict with the version of Go in -release.

[Michael Hudson-Doyle (mwhudson)]

golang-1.6 and golang-defaults packages are in http://people.canonical.com/~mwh/coinst-golang/. I'll chuck them in a PPA soon.

[Michael Hudson-Doyle (mwhudson)]

Ah yes, we also need to make the golang-race-detector-runtime package version dependent. That package is on people.c.c too now.

[Michael Hudson-Doyle (mwhudson)]

Packages are (or will be soon) in https://launchpad.net/~mwhudson/+archive/ubuntu/coinstallable-go/+packages

[Sebastien Bacher (seb128)]

those changes are not trivial, they proably need a ffe https://wiki.ubuntu.com/FreezeExceptionProcess

[Michael Hudson-Doyle (mwhudson)]

Yes, true. I was asked to do this by a release team member so hopefully that helps...

[Launchpad Janitor (janitor)]

This bug was fixed in the package gcc-5 - 5.3.1-12ubuntu1

---------------
gcc-5 (5.3.1-12ubuntu1) xenial; urgency=medium

  * Merge with Debian; remaining changes:
    - Build from upstream sources.

gcc-5 (5.3.1-12) unstable; urgency=medium

  * Update to SVN 20160315 (r234249, 5.3.1) from the gcc-5-branch.
    - Fix PR tree-optimization/69666, PR middle-end/69920, PR c++/67364,
      PR rtl-optimization/69195, PR rtl-optimization/47992,
      PR rtl-optimization/69941, PR target/70131 (rs6000).
  * When configured to link with --as-needed by default, always link the
    sanitizer libraries with --no-as-needed.
  * Fix PR c++/70209, taken from the trunk. LP: #1556217.
  * Stop providing alternative for /usr/bin/go. (Michael Hudson-Doyle).
    LP: #1555856.
  * Disable gnat on powerpcspe. Closes: #816051.
  * Apply proposed patch for PR c++/70218 (illegal access to private field
    succeeds). Closes: #70218.

 -- Matthias Klose <email address hidden> Thu, 17 Mar 2016 09:40:59 +0100

[Michael Hudson-Doyle (mwhudson)]

I've reported this as a bug in Debian: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=818415 and got the maintainers approval.

[Launchpad Janitor (janitor)]

This bug was fixed in the package gccgo-6 - 6-20160319-0ubuntu1

---------------
gccgo-6 (6-20160319-0ubuntu1) xenial; urgency=medium

  * Update to GCC 6 20160313.
  * Stop providing alternative for /usr/bin/go. (Michael Hudson-Doyle).
    LP: #1555856.

 -- Matthias Klose <email address hidden> Sat, 19 Mar 2016 12:27:27 +0100

[Michael Hudson-Doyle (mwhudson)]

The remaining packages are now in https://launchpad.net/~mwhudson/+archive/ubuntu/devirt/+packages

[Michael Hudson-Doyle (mwhudson)]

As is always the way I found a few silly things in the package (wrong bug syntax in changelog, overcomplication in a helper script, override_dh_prep was calling dh_clean and not dh_prep) and uploaded a +ppa1 package of golang-defaults. Can whoever sponsors the upload strip off the +ppa1 before uploading? TIA

[Michael Hudson-Doyle (mwhudson)]

We did an emergency golang update, so I've redone the packages in the ppa yet again. Comment about stripping {~,+}ppaN suffixes from versions remains...

[Michael Hudson-Doyle (mwhudson)]

All done now.