R devel - Oct 2014 - 'library' or 'require' call not declared from: 'rgl'

I'm checking a new release of vcdExtra via win builder with R-devel 
2014-10-29 r66897
and have run into a Warning I don't know how to fix.

I have one S3 generic, mosaic3d() that uses rgl and don't want to have 
rgl always loaded
via Depends:.  Instead, the mosaic3d.default() method includes

   if (!require(rgl)) stop("rgl is required")

This always worked in the past, but in this testing cycle, I got a slew 
of "no visible global function definition for ..."
all rgl functions.

I revised DESCRIPTION to include:

Imports:  rgl

and NAMESPACE:

import(rgl)

All the "no visible global function definition ..." went away, but
I'm
stuck with

* checking dependencies in R code ... WARNING
'library' or 'require' call not declared from: 'rgl'
See the information on DESCRIPTION files in the chapter 'Creating R
packages' of the 'Writing R Extensions' manual.

How can I solve this?

-- 
Michael Friendly     Email: friendly AT yorku DOT ca
Professor, Psychology Dept. & Chair, Quantitative Methods
York University      Voice: 416 736-2100 x66249 Fax: 416 736-5814
4700 Keele Street    Web:http://www.datavis.ca
Toronto, ONT  M3J 1P3 CANADA

> On Oct 30, 2014, at 3:11 PM, Michael Friendly <friendly at yorku.ca>
wrote:
> 
> I'm checking a new release of vcdExtra via win builder with R-devel
2014-10-29 r66897
> and have run into a Warning I don't know how to fix.
> 
> I have one S3 generic, mosaic3d() that uses rgl and don't want to have
rgl always loaded
> via Depends:.  Instead, the mosaic3d.default() method includes
> 
>  if (!require(rgl)) stop("rgl is required")
> 
> This always worked in the past, but in this testing cycle, I got a slew of
"no visible global function definition for ..."
> all rgl functions.
> 
> I revised DESCRIPTION to include:
> 
> Imports:  rgl
> 
> and NAMESPACE:
> 
> import(rgl)
> 
> All the "no visible global function definition ..." went away,
but I'm stuck with
> 
> * checking dependencies in R code ... WARNING
> 'library' or 'require' call not declared from:
'rgl'
> See the information on DESCRIPTION files in the chapter 'Creating R
> packages' of the 'Writing R Extensions' manual.
> 
> How can I solve this?
> 
Did you intend rgl to be optional? If so, then you should use Suggests: instead.
When you use Imports: it will load rgl automatically so require() does't
make sense (since it will be always TRUE).

Cheers,
Simon

> -- 
> Michael Friendly     Email: friendly AT yorku DOT ca
> Professor, Psychology Dept. & Chair, Quantitative Methods
> York University      Voice: 416 736-2100 x66249 Fax: 416 736-5814
> 4700 Keele Street    Web:http://www.datavis.ca
> Toronto, ONT  M3J 1P3 CANADA
> 
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