Can you provide links to your Poudriere build logs? Do so with every patch that requires build tests.
Regarding the commit message:

• use 'www/node: update prev_version -> new_version' title format
• skip parts like these, they're more justified for pkg message than for a commit message regarding port:
  
  'Bump to the latest major version of Node.js. This is a major release,

including many significant changes. Users are encouraged to read the
release announcement before upgrading:

https://nodejs.org/en/blog/release/v8.0.0/'

Any updates?

In D11030#228542, @robak wrote:

Can you provide links to your Poudriere build logs? Do so with every patch that requires build tests.

I will try. How persistent does the link need to be? I will host the log from my builder in EC2, which changes IP addresses fairly regularly (and doesn't have a permanent hostname).

Regarding the commit message:

• use 'www/node: update prev_version -> new_version' title format

Will do.

• skip parts like these, they're more justified for pkg message than for a commit message regarding port:
  
  'Bump to the latest major version of Node.js. This is a major release,

including many significant changes. Users are encouraged to read the
release announcement before upgrading:

https://nodejs.org/en/blog/release/v8.0.0/'

I was thinking about including an UPDATING entry, or do you think a pkg-message is better?

As you can see from my poudriere logs, this does not build on 11.1-BETA3 or 12.0-CURRENT with clang 4.0. Removing the _LIBCPP_TRIVIAL_PAIR_COPY_CTOR=1 define fixes the build with clang 4.0, but then breaks the build on 10.3-R and 11.0-R using clang 3.x. I am trying to see if I can find a way to get it to build everywhere before considering adding a dependency on devel/clang40 on 10.3-R and 11.0-R.

Can you try with gcc to check if the problem is with clang or somewhere else?

It does appear to be a clang problem:

https://bugs.llvm.org/show_bug.cgi?id=18249
https://bugs.llvm.org/show_bug.cgi?id=18350
https://bugs.llvm.org/show_bug.cgi?id=18853

I am currently testing a Makefile change to add the _LIBCPP_TRIVIAL_PAIR_COPY_CTOR conditionally if we are using clang < 4.0. I will update the patch if it works :)