capabilities() and non-catchable messages

Do you have DISPLAY set pointing to an X11 server you do not have 
access to?  It seems so.  The solution is to set your X11 settings 
properly.

This is coming from Xlib (XOpenDisplay, I believe) and so is not an R 
error or warning, and is not output on an R connection but on a  C file.

On Mon, 20 Jun 2005, Henrik Bengtsson wrote:

Just for the record (not a request for fix) and an ad hoc workaround if
anyone needs it:

REASON:
Running an R script as a plugin on a remote Suse Linux 8.2 with R v2.1.0
(2005-04-18), I have noticed that capabilities() generates (to standard
error)

 Xlib: connection to "base:0.0" refused by server
 Xlib: Client is not authorized to connect to Server

which cannot be caught by tryCatch();

 tryCatch({
   print(capabilities());
 }, condition=function(c) {
   cat("Condition caught:\n");
   str(c);
 })

because it is not a 'condition' (error or warning).

CONTEXT:
Since source() calls capabilities("iconv") this messages always show up.
My R plugin loads custom code using source() and since the standard
error from the plugin is checked for messages, the host system
interprets this as if something problematic has occured.

WORKAROUND:
The workaround that I use now is to redefine capabilities() temporarily
(since I do not need "iconv" support):

orgCapabilities <- base::capabilities;
basePos <- which(search() == "package:base"));
assign("capabilities", function(...) FALSE, pos=basePos);

source(<my file>)

basePos <- which(search() == "package:base"));
assign("capabilities", orgCapabilities, pos=basePos);
rm(orgCapabilities)

Cheers

Henrik