Allow user install

[Tim Kientzle]

On Jun 26, 2012, at 3:54 AM, Dag-Erling Smørgrav wrote:

> Simon Gerraty <sjg at juniper.net> writes:
>> The patch below is a step towards supporting unprivileged buildworld
>> etc.  Eg.
> 
> Wow, this is really cool - and long overdue.
> 
> I've been thinking for a while that some bor^H^H^Henterprising soul
> should hack install(1) so that if a specific environment variable is
> set, it writes the file to a tarball instead of writing it to disk.
> Unfortunately, there would still be a ton of ${LN} etc. that would need
> to be handled somehow.

Better idea:  have the build write a textual description of the
tar entries.  That description can then be fed to tar to build
the actual tarball.

The description format that tar already supports is a variant
mtree format borrowed from NetBSD.  Each line specifies
the tar entry fields (filename, owner, permissions, etc) and
the filename where the file contents are stored.

Tim