USE_LANGUAGES=c++11 but no C++ 11 compiler (NetBSD 7.1)

["Sijmen J. Mulder" <ik%sjmulder.nl@localhost>]

Hi,

textproc/libxls nowadays requires a C++11 compiler and the
package Makefile accounts for this:

  USE_LANGUAGES=  c c++11

However, its build failed on NetBSD 7.1 because it looks like no C++11
compiler was used:

  checking whether c++ supports C++11 features with -std=gnu++11... no
  checking whether c++ supports C++11 features with -std=gnu++0x... no
  checking whether c++ supports C++11 features with -std=c++11... no
  checking whether c++ supports C++11 features with +std=c++11... no
  checking whether c++ supports C++11 features with -h std=c++11... no
  checking whether c++ supports C++11 features with -std=c++0x... no
  checking whether c++ supports C++11 features with +std=c++0x... no
  checking whether c++ supports C++11 features with -h std=c++0x... no
  configure: error: *** A compiler with support for C++11 language features is required.

https://us-east.manta.joyent.com/pkgsrc/public/reports/Linux/el6/trunk/x86_64/20190605.0004/libxls-1.5.1/configure.log

The question being, is there no mechanism in pkgsrc to build and use a better compiler (e.g. LLVM or a newer GCC) if required?

(I will set up 7.1 locally to test more)

Sijmen