[MacPorts] #57061: glib2 @2.56.2: won't build +universal if libgcc7 installed

[MacPorts]

#57061: glib2 @2.56.2: won't build +universal if libgcc7 installed
---------------------------+------------------------
 Reporter:  kencu          |      Owner:  ryandesign
     Type:  defect         |     Status:  assigned
 Priority:  Normal         |  Milestone:
Component:  ports          |    Version:
 Keywords:  tiger leopard  |       Port:  glib2
---------------------------+------------------------
 This is a niche situation, admittedly, disappearing from MacPorts.

 building glib2 +universal fails on Tiger (and presumably Leopard) if
 `libgcc7` is installed and active.

 configuration of `glib2` fails when it tries to find a compatible
 `libiconv_open` to use. It finds `/opt/local/lib/libstdc++.6.dylib`
 installed by `libgcc7` which is only built in the host architecture, and
 errors out.

 However, if `libgcc7` is deactivated, then configure finds
 `/usr/lib/libstdc++.6.dylib` instead, which is multiarchitecture and fat,
 and the universal build succeeds without issue.

 I'm not sure if `glib2` can be set up to find `/usr/lib/libstdc++.6.dylib`
 preferentially. In the meantime, deactivating `libgcc7`, upgrading
 `glib2`, and then reactivating `libgcc7` is a fairly trivial workaround.

-- 
Ticket URL: <https://trac.macports.org/ticket/57061>
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