[illumos-Developer] Future branch version for illumos-gate IPS packages

[Albert Lee]

illumos-gate currently produces pkg(5) packages with the "branch
version" frozen at "0.148", corresponding to the fork from OpenSolaris
ON occurring in the middle of build 148 development.

The branch version is the last component of the version number
"0.5.11,5.11-0.148" (excluding the timestamp) for most packages in
illumos.

The OpenIndiana distribution, as OpenSolaris did (and Solaris 11
Express continues to do), uses a global branch version for all
packages corresponding to a release, such as 0.151. If an illumos-gate
build uses 0.148, onu may refuse install it on a system whose
installed build is 0.151, because it appears as a "downgrade" to
packaging.

The build number portion of the branch version can be adjusted by
adding to illumos.sh:
  ONNV_BUILDNUM=xxx; export ONNV_BUILDNUM

Changing ONNV_BUILDNUM has no effect outside of the IPS packaging
branch version. An illumos-gate build with a larger or equal branch
version with a newer timestamp will always be considered an upgrade by
onu.

The build number in the branch version is no longer meaningful to
illumos itself; incrementing it will only cause confusion as they
overlap Oracle build numbers.

My preference is to change the default branch version to "1.0" which
satisfies upgrading with distros using "0.x" branch numbers. (Rich
seems to agree with this). We may later apply a versioning scheme that
utilises the branch version as long as we only increase that number.
Another reasonable suggestion is to use the branch version of the
packages installed on the build system (probably osnet-incorporation)
as a default, although this may result in builds which are identical
except for packaging (on the other hand, different build systems may
result in different external dependencies).

Again, this change has no effect outside of the IPS packaging branch version.

-Albert