This is currently how we run the "solaris-amd64" builder but it's
really illumos and once we have GOOS=illumos vs GOOS=solaris split
(https://golang.org/issue/52630), then this will need work to rebuild
the images.

This runs on Joyent:

   Username: gobuild
   Password: http://go/golang-joyent

To create a working image:

* Create a new Infrastructure Container instance from the "base-64" image
* ssh in as root (account will have key info)
* Copy the build key to the machine at /root/.gobuildkey
* Download the stage0:

  cd /opt
  /opt/local/bin/curl -f -R \
    -z buildlet-stage0 \
    -o buildlet-stage0 \
    https://storage.googleapis.com/go-builder-data/buildlet-stage0.solaris-amd64
  chmod +x /opt/buildlet-stage0

* Install gcc:

  pkgin in gcc47

* Copy buildlet.xml to the machine anywhere
* Run as root:
  svccfg import buildlet.xml

Service should be running now.  Shut down the machine and create an image from
the Joyent web console.

If you need to debug, you can check status with:

svcs -x buildlet.xml

This will also give you the location to the log file.

If you need to change an environment variable, place this inside the start
exec_method element:

<method_context>
        <method_environment>
                <envvar name="EXAMPLE" value="foo"/>
        </method_environment>
</method_context>


To debug an instance once it's running, you can ssh as:

$ ssh -i ~/.ssh/id_rsa_golang2 root@$IP

The key is at http://go/id_rsa_golang2