[Rd] how to catch useDynLib errors? Rgraphviz

[Martin Morgan]

Rgraphviz load problems frequently involve a mismatch between the
version of graphviz installed on the user machine, compared to the
version of graphviz used to build the package.

Rgraphviz has a name space with useDynLib(Rgrahpviz), and an .onLoad
function that checks that the versions of the installed and built
graphviz match. Unfortunately, the .onLoad code is only evaluated if
useDynLib succeeds, so in many cases of version mismatch users receive
hard-to-interpret error messages.

Are there any hooks or other solutions available to catch errors during
useDynLib? Or will we have more success using library.dynam in .onLoad?

Thanks in advacne

Martin
-- 
Martin Morgan
Computational Biology / Fred Hutchinson Cancer Research Center
1100 Fairview Ave. N.
PO Box 19024 Seattle, WA 98109

Location: Arnold Building M1 B861
Phone: (206) 667-2793