[MacPorts] #38374: boost: stdlibc++ linkage prevents dependencies from using libc++

[MacPorts]

#38374: boost: stdlibc++ linkage prevents dependencies from using libc++
----------------------------+---------------------------
  Reporter:  macportbugs@…  |      Owner:  adfernandes@…
      Type:  defect         |     Status:  new
  Priority:  Normal         |  Milestone:
 Component:  ports          |    Version:  2.1.3
Resolution:                 |   Keywords:
      Port:  boost          |
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Comment (by adfernandes@…):

 For my two cents, I agree with `jeremyhu`, but only sort-of. For sure the
 `boost` build system should respect the system `configure.cxx` setting.
 ''However'', it is sad fact of life that the boost build system does not,
 by default, support this.

 I will warn everyone that using `libc++`, while it appears to work, may
 not ''actually'' work since this configuration is not supported nor tested
 by the `boost` team on MacOS.

 I can patch the `Portfile` such that
 {{{
 write_jam "using darwin : : ${configure.cxx} :
 <cxxflags>\"${configure.cxxflags}\" <linkflags>\"${configure.ldflags}\" :
 ;"
 }}}
 with an include-guard to make sure that all variables are set, etc.

 The problem we're having is that, as part of MacPorts, `boost` really
 should be built as if it were a system library, that is, with all build
 values at default. What people ''want'' is a `boost` installation that is
 customized for their particular project. As `jeremyhu` points out, then we
 start to mix `libc++` ABIs, and weird breakage results.

 Any thoughts from anyone before I patch the Portfile as above?

-- 
Ticket URL: <https://trac.macports.org/ticket/38374#comment:8>
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