[R-pkg-devel] Winbuilder error for rgl on R 3.6.3

Dear R experts,

I am testing my R package 'fsbrain' using the Winbuilder service [1] before submitting a new version to CRAN.

All checks pass under R versions 4.0.5 and 4.1.0 alpha, but the installation fails under R 3.6.3 because of a problem related to rgl, which is a dependency of my package.

The file 00check.log says 'installation failed' and refers to '00install.log', which contains the following message:

------------------Message start-------------------------
* installing *source* package 'fsbrain' ...
** using staged installation
** R
** inst
** byte-compile and prepare package for lazy loading
Error in system.file(paste0(dir, "/rgl", .Platform$dynlib.ext), package = pkg,  :
   no file found
Warning: 	Loading rgl's DLL failed.
Warning: Trying without OpenGL...
Error in system.file(paste0(dir, "/rgl", .Platform$dynlib.ext), package = pkg,  :
   no file found
Error: .onLoad failed in loadNamespace() for 'rgl', details:
   call: fun(libname, pkgname)
   error: Loading failed.
Execution halted
ERROR: lazy loading failed for package 'fsbrain'
* removing 'd:/RCompile/CRANguest/R-oldrelease/lib/fsbrain'
* restoring previous 'd:/RCompile/CRANguest/R-oldrelease/lib/fsbrain'
------------------end-------------------------

The full output of the build process can currently be found at https://win-builder.r-project.org/5Mr7luWmfUNL/

To me it seems that rgl cannot be loaded on the test system, but I do not fully understand the message and what to do about it. I hope somebody here can comment on the message and suggest a solution.

The source code for my package is at https://github.com/dfsp-spirit/fsbrain.

Thanks for your time,

Tim

[1] https://win-builder.r-project.org

--
Dr. Tim Sch?fer
Postdoc Computational Neuroimaging
Department of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy
University Hospital Frankfurt, Goethe University Frankfurt am Main, Germany