gimp2 @2.10.14: A compiler with support for C++14 language features is required

[ryandesign (Ryan Carsten Schmidt)]

Even though gimp2 specifies compiler.cxx_standard 2014, ​gimp2 doesn't build on 10.9 at least:

checking whether /usr/bin/clang++ supports C++14 features by default... no
checking whether /usr/bin/clang++ supports C++14 features with -std=gnu++14... no
checking whether /usr/bin/clang++ supports C++14 features with -std=gnu++1y... no
checking whether /usr/bin/clang++ supports C++14 features with -std=c++14... no
checking whether /usr/bin/clang++ supports C++14 features with +std=c++14... no
checking whether /usr/bin/clang++ supports C++14 features with -h std=c++14... no
checking whether /usr/bin/clang++ supports C++14 features with -std=c++1y... no
checking whether /usr/bin/clang++ supports C++14 features with +std=c++1y... no
checking whether /usr/bin/clang++ supports C++14 features with -h std=c++1y... no
configure: error: *** A compiler with support for C++14 language features is required.

It was discussed recently that MacPorts base might have the wrong idea about which compiler versions are compatible with which C++ standards.

[dbevans (David B. Evans)]

In 41c5876665f7266f6d0b36994f639a352d7ff295/macports-ports (master):

gimp2: restore previous blacklisting

Hopefully restores build on 10.9.

Closes #59635

[ryandesign (Ryan Carsten Schmidt)]

Ok but it would also be good to fix the problem in MacPorts base​, if indeed the versions there are wrong.