R_LIBS_SITE and RStudio Server

Hello,

we build the latest release of RStudio Server 1.3 from source since the changed 1.4 authentication does not work in our settings (using the Open OnDemand HPC portal), and we need to port in some more recent updates (support for R graphics 14).

We have R 4.1.1 built with R_LIBS_SITE set to where we install the system-wide R libraries, e.g.:

$ echo $R_LIBS_SITE
/uufs/chpc.utah.edu/sys/installdir/RLibs/4.1.1

Then I start RStudio server as:
$ echo RSPATH /uufs/chpc.utah.edu/sys/installdir/rstudio-server/1.3.1093-chpc/bin {RSPATH}/rserver
--www-port {port} \ --auth-none 0 \ --auth-pam-helper-path "{RSTUDIO_AUTH}"
--auth-encrypt-password 0
--rsession-path "{RSESSION_WRAPPER_FILE}" \ --server-data-dir "{TMPDIR}"
--secure-cookie-key-file "${TMPDIR}/rstudio-server/secure-cookie-key"

and in the RSESSION_WRAPPER_FILE shell script calls the rsession as:
{RSPATH}/rsession --r-libs-user "{R_LIBS_USER}" "${@}"

Now, when in the RStudio session, I get empty R_LIBS_SITE:

sys.getenv()
...
R_LIBS_SITE
...

I did manage to get this in through the Renviron file (in our case located at /uufs/chpc.utah.edu/sys/installdir/R/4.1.1/lib64/R/etc/Renviron), but, it'd be more flexible to use the R_LIBS_SITE.

Any thoughts why the R_LIBS_SITE is being ignored?

Thanks,
Martin