[Rd] [2 of n] Revisiting and updating reproducible builds for base R in Debian

[Dirk Eddelbuettel]

tl;dr: Some progress, but some issues remaining which may require assistance.


Thanks again to Gabe for noticing that one-off install step in package
'tools' I had not been aware of.  Ensuring that an override-timestamp is
passed there too addressed this difference in subsequent builds moving us
closer to reproducible builds.

I also addressed (so far by 'brutish force') one issue with the pdf docs made
from help pages.  The help page for Rd2HTML demonstrates how a help can
reflect Sexpr content at 'build', 'install', and 'render' time calling
Sys.time() three times. This is obviously incompatible with reproducible 'bit
by bit' identical builds so I (for now) commented that example out; I may try
to see with Duncan what else we may do here.

Which gets us to the current state of affairs. Package r-base-core still
shows difference which can be seen following the most recent build this
browseable report:

https://tests.reproducible-builds.org/debian/rb-pkg/unstable/amd64/diffoscope-results/r-base.html

There are difference in

 - the installed libtool script (and I may see about help from the
   reproducibe builds team)
   
 - methods/Meta/package.rds and methods/Meta/package.rdb and
   methods/Meta/package.rdx: these have me stumped, and I am not all familiar
   what goes into these files

 - tools/help/tools.rdb and tools/help/tools.rdx: Also unclear

 - usr/share/man/man1/R.1.gz and usr/share/man/man1/Rscript.1.gz: both carry
   an 'installed at' timestamp, this should be addressable (but I have yet to
   look closely).

If anybody reading this far (thanks for that!) knows about the R package
internal files, and how we might tweak the creation of these files, please do
not hesitate to reach out.  We as close as we've been on this and may get
this over the goal line.

Cheers, Dirk

-- 
dirk.eddelbuettel.com | @eddelbuettel | edd using debian.org