rgdal installation with two versions of GDAL

You can *really* confirm where things are found via R CMD ldd ... see
the manual.

Yes of course. I had done that, and received the hoped-for response:

libgdal.so.1 => /opt/gdal-1.11.2/lib/libgdal.so.1 (0x00007fd9e0175000)

But I realize now that this was with LD_LIBRARY_PATH set. Of course R
modifies LD_LIBRARY_PATH, erasing any paths set by the user, so that while
the installation succeeds, the load doesn't.

I've temporarily modified ldpaths and it works. So there's the answer for
now.

But (see the posting guide) the generic question belonged on R-devel and

questions about rgdal on R-sig-geo.

Apologies. I'll ask there next time.

Rob