[BioC] warning if pdf of vignette is missing

[Seth Falcon]

On 16 Sep 2005, huber at ebi.ac.uk wrote:
> as far as I understand, you can safely ignore this Warning.

I have a different opinion.  Vignettes are an important component of
BioC packages.  If R CMD build isn't building them, that usually
indicates a problem that needs fixing.

If we can help get the vignette building, post some details about what
is going on.

Best,

+ seth