[R] R_LIBS var needed to be set after upgrade to R 4.2.2

[Martin Maechler]

>>>>> Ashim Kapoor 
>>>>>     on Wed, 1 Jun 2022 14:30:58 +0530 writes:

    > Dear Sir,
    >> > I upgraded to R 4.2.2  on Debian 10 today.
    >> 
    >> Well, I assume you mean R 4.2.0 .. at least that one exists.

    > My bad, yes I made a typo. I did mean R 4.2.0.

    >> > The R shell incantation worked fine and all libraries would load but,
    >> > I needed to point the R_LIBS variable to
    >> > /usr/local/lib/R/site-library/ in order for the R --vanilla < myfile.R
    >> > incantation to find the libraries.
    >> 
    >> you mean other installed *packages*
    >> 
    >> > May I ask, why was this ? I never needed to do this on any previous
    >> > upgrade to R.
    >> 
    >> Well,  for me, the     R --vanilla   form also only sees the
    >> 29 (14 "base" + 15 "Recommended") packages that come with R.

    > Has this ALWAYS been the case for you ? Even with prior versions of R ?

Yes; I'm sorry this was unclear.

    >> Debian (& Ubuntu etc)  have used a similar setup where the
    >> default {R-level}  .libPaths() has contained three libraries,
    >> via
    >> 
    >> R_LIBS_SITE=${R_LIBS_SITE-'/usr/local/lib/R/site-library:/usr/lib/R/site-library:/usr/lib/R/library'}
    >> 
    >> see
    >> 
    >> https://cloud.r-project.org/bin/linux/debian/#pathways-to-r-packages
    >> 
    >> also for much more.
    >> Note (also from the above CRAN page
    >> https://cloud.r-project.org/bin/linux/debian/
    >> [ Remember "menu"  "Binaries" -> "Linux" -> "Debian" ]
    >> 
    >> The good thing about the Debian (and derivatives) setup is that
    >> it also separates (as I do) the  "packages that come with R" in
    >> one library (= /usr/lib/R/library) from packages that are
    >> installed differently.

    > My confusion is : Earlier R --vanilla incantation was working fine,
    > even without my intervening and
    > adding to R_LIBS. That is why I was confused.

    > My main query is : Is there anything special to R 4.2.0 which needs
    > R_LIBS to be setup seperately?

to which Jeroen Ooms answered nicely -- thank you, Jeroen!

    > I was hit by this problem as well a few weeks ago. You may get a more
    > detailed answer in r-sig-debian or from Dirk directly, but from what I
    > understood, this is now expected behavior: indeed if you start R
    > --vanilla then /usr/local/lib is no longer included in the library path.

    > The reason is that R-core made a change in 4.2.0 to pre-set values for
    > R_LIBS_USER and R_LIBS_SITE in Renviron [1] which would take
    > precedence over the proper distro defaults (that include
    > /usr/local/lib) as configured by the r-base deb/rpm packages. To
    > mitigate the problem the r-base deb package moved the appropriate
    > R_LIBS_USER and R_LIBS_SITE definitions into Renviron.site, which
    > takes precedence over Renviron. However a side effect of this solution
    > is that Renviron.site is ignored in --vanilla mode. At least this is
    > my best understanding of the problem.

    > [1] https://cran.r-project.org/doc/manuals/r-release/NEWS.html

Yes, as

     R --help | grep -A1 -e --vanilla | head -2

has given
 
  --vanilla		Combine --no-save, --no-restore, --no-site-file,
			--no-init-file and --no-environ

(unchanged for many years).


Being a Linux user of more than 25 years, I've not been much of a
Debian-or-derivatives user in recent years (apart from setting up
and maintaining Ubuntu LTS on my wife's computer) mainly because
of lazyness as our IT staff helps me solve all problems with
Fedora quickly, including lowelevel device-related ones,
I think that Debian(+derivatives) has always been the exception
among the Linux distros and for all the others, '--vanilla'
really meant "vanilla" in a loose sense, i.e., "just base R".

I agree that I had wanted a "vanilla+strawberry" version myself, really.
which would be just not have the  --no-site-file  switch,
so we could call it
   --vanilla+site

{Others may hate  "feature creep" and yet more output from
'R --help'  ..}

Martin