[MacPorts] #62183: ruby30 @3.0.0: error: use of undeclared identifier 'fmt'; did you mean 'fma'?

[MacPorts]

#62183: ruby30 @3.0.0: error: use of undeclared identifier 'fmt'; did you mean
'fma'?
--------------------------+----------------------
  Reporter:  simon-dedeo  |      Owner:  kimuraw
      Type:  defect       |     Status:  assigned
  Priority:  Normal       |  Milestone:
 Component:  ports        |    Version:  2.6.4
Resolution:               |   Keywords:  sierra
      Port:  ruby30       |
--------------------------+----------------------

Comment (by simon-dedeo):

 In case it helps, I managed to get the installation to work with the
 following trick. Obviously this is not the way someone wants to do it in
 the long term! It's based on reading (via Google translate) the remarks at
 https://koic.hatenablog.com/entry/update-clang-for-ruby-2-8-0-dev which
 suggest that it's the version of clang that's causing trouble. If it is
 indeed clang-9, this might explain why both lower and higher versions of
 Mac OS X than 10.12 are able to install 3.0.

 First, update clang to 11 (at least that's what I did):

 {{{ sudo port install clang-11 }}}

 {{{ port select --set clang mp-clang-11 }}}

 Then, try to install ruby30; when it crashes do the following as superuser
 (if necessary):

 {{{ cd
 /opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_release_tarballs_ports_lang_ruby30/ruby30/work/ruby-3.0.0
 }}}

 {{{ ./configure --prefix=/opt/local --enable-shared --enable-install-
 static-library --disable-install-doc --mandir=/opt/local/share/man
 --enable-pthread --without-gmp --with-opt-dir=/opt/local --program-
 suffix=3.0 --with-rubylibprefix=/opt/local/lib/ruby3.0 --without-baseruby
 --with-arch=x86_64 CC=/opt/local/bin/clang }}}

 {{{ make clean }}}

 Finally, run {{{ sudo port install ruby30 }}} again.

 This forces the port to install with the clang-11 compiler; the magic is
 the final additional option.

-- 
Ticket URL: <https://trac.macports.org/ticket/62183#comment:7>
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