[MacPorts] #57911: libcxx @5.0.1_4: cc1plus: error: unrecognized command line option "-Wsign-conversion"

[MacPorts]

#57911: libcxx @5.0.1_4: cc1plus: error: unrecognized command line option "-Wsign-
conversion"
-------------------------+----------------------
  Reporter:  ryandesign  |      Owner:  jeremyhu
      Type:  defect      |     Status:  assigned
  Priority:  Normal      |  Milestone:
 Component:  ports       |    Version:
Resolution:              |   Keywords:  leopard
      Port:  libcxx      |
-------------------------+----------------------

Comment (by ryandesign):

 I tried replacing
 {{{
 compiler.blacklist *gcc* {clang < 500}
 }}}
 with
 {{{
 compiler.blacklist *gcc-3.* *gcc-4.* {clang < 500}
 }}}
 but that resulted in:
 {{{
 Error: Cannot install libcxx for the archs 'i386 ppc' because
 Error: its dependency gcc6 cannot build for the required archs.
 Error: Problem while installing libcxx
 }}}

-- 
Ticket URL: <https://trac.macports.org/ticket/57911#comment:2>
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