[MacPorts] #65945: jemalloc fails on 10.5.8: Undefined symbols: _malloc_default_purgeable_zone, __Unwind_Resume using a modified MacPorts setup on 10.5 that is defaulting to use gcc11

[MacPorts]

#65945: jemalloc fails on 10.5.8: Undefined symbols:
_malloc_default_purgeable_zone, __Unwind_Resume using a modified MacPorts
setup on 10.5 that is defaulting to use gcc11
---------------------------+-------------------------------------------
  Reporter:  barracuda156  |      Owner:  kencu
      Type:  defect        |     Status:  assigned
  Priority:  Normal        |  Milestone:
 Component:  ports         |    Version:  2.7.2
Resolution:                |   Keywords:  powerpc, leopard, snowleopard
      Port:  jemalloc      |
---------------------------+-------------------------------------------

Comment (by kencu):

 to use weak linking, where the symbol is not available at build time, with
 macOS, it seems you need to add this flag during linking:

 {{{
 -undefined dynamic_lookup
 }}}

 so the fix would be to add something like this when building on < 10.6:

 {{{
 configure.ldflags-append '-Wl,-undefined,dynamic_lookup'
 }}}

-- 
Ticket URL: <https://trac.macports.org/ticket/65945#comment:20>
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