[MacPorts] #13693: Fix compilation of gnustep-base

[MacPorts]

#13693: Fix compilation of gnustep-base
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  Reporter:  fedor at qwest.net  |       Owner:  ryandesign at macports.org
      Type:  enhancement      |      Status:  new                    
  Priority:  Normal           |   Milestone:  Port Enhancements      
 Component:  ports            |     Version:  1.5.2                  
Resolution:                   |    Keywords:                         
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Comment (by ryandesign at macports.org):

 Thanks for the suggestion! I modified your patch a little: to make it
 clearer to the user that there's a choice between ffi and ffcall, I made
 two conflicting variants, ffi and ffcall, with ffi the default. I also
 added variant descriptions. I don't hold with the "with_foo" variant
 naming strategy, so they're just called ffi and ffcall. See r32265.

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Ticket URL: <http://trac.macosforge.org/projects/macports/ticket/13693#comment:2>
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