[MacPorts] #64247: openrct2: builds failing for 10.13 and earlier, with macports-libcxx: cyclic dependency errors

[MacPorts]

#64247: openrct2: builds failing for 10.13 and earlier, with macports-libcxx:
cyclic dependency errors
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  Reporter:  mascguy   |      Owner:  mascguy
      Type:  defect    |     Status:  assigned
  Priority:  Normal    |  Milestone:
 Component:  ports     |    Version:
Resolution:            |   Keywords:
      Port:  openrct2  |
-----------------------+----------------------

Comment (by mascguy):

 Replying to [comment:2 kencu]:
 > Assuming this is related to c++ modules, as it appears to be, this issue
 has so far been not trivial to work around.
 >
 > They make the SDK headers in one place use other headers in that place,
 ignoring your header include paths.

 Ken, while I'm still a bit foggy on the interactions, what is driving the
 behavior? For example, is it rigid header/path inclusion enforced via the
 toolchain, which can't be overridden? Or...?

 Ultimately I'm just trying to understand where the issue is, and whether
 it would be feasible for us to sidestep it.

-- 
Ticket URL: <https://trac.macports.org/ticket/64247#comment:4>
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