[MacPorts] #44125: cmake needs to support building against / with a deployment target set (prevents libc++ support on Snow Leopard for cmake projects)

[MacPorts]

#44125: cmake needs to support building against / with a deployment target set
(prevents libc++ support on Snow Leopard for cmake projects)
---------------------------+--------------------------------
  Reporter:  mojca@…       |      Owner:  macports-tickets@…
      Type:  defect        |     Status:  closed
  Priority:  Normal        |  Milestone:
 Component:  ports         |    Version:
Resolution:  fixed         |   Keywords:
      Port:  cmake libcxx  |
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Comment (by jeremyhu@…):

 Replying to [comment:17 mojca@…]:
 > Replying to [comment:15 jeremyhu@…]:
 > >
 > > > On the other hand I understand that setting target to 10.6 on 10.7
 without specifying the SDK might render the resulting binary useless on
 10.6.
 > >
 > > Why do you say that?  The whole point of setting the deployment target
 to 10.6 means that the resulting binary will work on 10.6 unless there's a
 bug in the toolchain for some reason (which setting the sysroot won't
 solve).
 >
 > My personal experience is that setting just `-mmacosx-version-min=10.x`
 isn't always enough to get functional binaries.

 It is supposed to be.

 > But just `-mmacosx-version-min=10.5` certainly wasn't enough. The
 binaries kept crashing on 10.5 if I didn't set the `isysroot`. (But I no
 longer have a 10.5 machine to repeat the experiment.)

 What was the crash?  I suspect the problem was with the application making
 assumptions that were not valid and not properly checking for possibly-
 weak symbols due to functionality added by newer releases.

 > There is also "hardcoded" SDK in
 [browser:trunk/dports/graphics/wxWidgets-2.8/Portfile wxWidgets-2.8] (see
 also the [browser:trunk/dports/_resources/port1.0/group/wxWidgets-1.0.tcl
 wxWidgets PortGroup]). From what I remember wxWidgets 2.8 doesn't compile
 on 10.7 unless the SDK for 10.6 is explicitly set.

 Why?  Is that because they hardcoded OS X versions like QT does such that
 they automatically complain or fail on new versions of the OS?

-- 
Ticket URL: <https://trac.macports.org/ticket/44125#comment:18>
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