[R] R_LIBS_SITE in Renviron ignored (?)

[Sebastian Schubert]

Hi all,

I am on CentOS 7.2 (Linux x86_64) with R from EPEL.

Maybe I get the documentation wrong but it seems, the variable
R_LIBS_SITE in Renviron is ignored while, for example, R_LIBS_USER is
not.

What R tells me:

R version 3.3.1 (2016-06-21) -- "Bug in Your Hair"
...
Platform: x86_64-redhat-linux-gnu (64-bit)
...
> .libPaths()
[1] "/usr/lib64/R/library" "/usr/share/R/library"
> .Library
[1] "/usr/lib64/R/library"
> .Library.site
[1] "/usr/lib64/R/library" "/usr/share/R/library"
> R.home(component = "home")
[1] "/usr/lib64/R"

However, the respective Renviron includes the following:
# grep R_LIBS_SITE /usr/lib64/R/etc/Renviron
R_LIBS_SITE=${R_LIBS_SITE-'/usr/local/lib/R/site-library:/usr/local/lib/R/library:/usr/lib64/R/library:/usr/share/R/library'}

Apparently, this setting is not applied when I start R. However,
changes for example in R_LIBS_USER in the same file are applied, thus
the file must be read...

I don't see where R_LIBS_SITE could be overwritten elsewhere. I get
the same behaviour in R when I start it with

R --no-environ --no-site-file --no-init-file

Any idea?

Thanks a lot,
Sebastian