Enabling the WITH_REPRODUCIBLE_BUILD knob for 12.0-REL

[Ed Maste]

On 10 September 2018 at 12:51, Rodney W. Grimes
<freebsd-rwg at pdx.rh.cn85.dnsmgr.net> wrote:
>
> Why not just turn this on and leave it on?

I know a number of developers want to keep the metadata for their own
builds at least.

We have essentially three different levels of metadata that are
arguably sensible:

1. Major/minor version, release/branch name, architecture
2. Version control information
3. Path, user, date, time, host

And three kinds of working trees:

1. Non-versioned with/without modifications (e.g., a src tarball)
2. git/svn/other checkout, without modifications
3. git/svn/other checkout, with modifications

What I'm proposing for 12.0 gives us 1+2 always (regardless of the
state of the tree).

I think there's more discussion to be had on the mapping between the
tree type/state and amount of metadata to include. If we come to a
consensus I'll handle it, but don't want to hold up a change destined
for 12.0 with a broader discussion.