[R-SIG-Mac] (old) rgl package crashes MacGUI using R 3.2.3 in El Cap, new compiled one does not.

[Duncan Murdoch]

On 30/12/2015 9:40 PM, David Winsemius wrote:
[lots deleted]
> So I guess the question is ... why is the build process for the Mavericks/Yosemite/El Capitan machines still failing to produce a current (working) version of rgl?

I think it does probably does produce a working version, but it fails 
the tests on that particular machine.

I believe the problem is that the CRAN test machine uses an unusual X 
server.  I've asked for details on a couple of occasions so I could 
reproduce the error, but received no response.  I don't know if the 
server is buggy or rgl just fails to do some checks that are unnecessary 
on other servers.

The latest error is occurring in rgl.pixels, and the underlying C++ code 
there is a little sloppy with type conversions (e.g. it assumes GL_FLOAT 
is float, which is not necessarily true), and is probably also sloppy 
with run-time checks.  I don't think the type sloppiness could be a 
cause of the error (I think it would fail for all servers if so), and I 
can't spot the run-time sloppiness.

Duncan Murdoch