pkg/54032: cmake requires -std=c++1z

[clare%csel.org@localhost]

>Number:         54032
>Category:       pkg
>Synopsis:       cmake requires -std=c++1z
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    pkg-manager
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Sat Mar 02 13:15:01 +0000 2019
>Originator:     Shinichi Doyashiki
>Release:        NetBSD 8.99.28
>Organization:
	at home
>Environment:
System: NetBSD yukine.csel.org 8.99.28 NetBSD 8.99.28 (GENERIC) #0: Mon Dec 24 20:48:00 JST 2018 clare%test0.csel.org@localhost:/export/stage/hack/objdir.amd64/sys/arch/amd64/compile/GENERIC amd64
Architecture: x86_64
Machine: amd64
>Description:
	the cmake package requires special CXXFLAGS.
	if doing plain build, it fails as following:

CMake Error at CMakeLists.txt:92 (message):
  The C++ compiler does not support C++11 (e.g.  std::unique_ptr).

>How-To-Repeat:
	cd ${PKGSRC}/devel/cmake && make update
>Fix:
	to a workaround, run make as following:
	# env CXXFLAGS="-O3 -std=c++1z" make update