change libcxx +emultated_tls to installing a binary please on < 10.7...

[Ryan Schmidt]

On Dec 1, 2020, at 00:07, Ken Cunningham wrote:

> another reasonably simple option would be to have a manual step, and copy what happens with apple-gcc42 +bootstrap.
> 
> 
> We make up a non-TLS variant of libcxx, call it libcxx +bootstrap, and default to installing that if there is nothing in /usr/lib/libc++.dylib.
> 
> Then the port notes (like apple-gcc42) would tell people what to do:
> 
> require the installation of clang-5.0, then run:
> 
> sudo port install libcxx -bootstrap
> 
> and that gets the binary installed.
> 
> From then on, people would just have to 
> 
> sudo port install libcxx 
> 
> and they would get the TLS version.

apple-gcc42's +bootstrap variant is not suitable for the buildbot either because of that manual step. The solution would be to change it to a apple-gcc42-bootstrap subport that installs its files somewhere else, and apple-gcc-42 (non-bootstrap) knows how to use those files to build itself.