[MacPorts] #64869: PDAL @2.3.99.1: fatal error: 'filesystem' file not found

[MacPorts]

#64869: PDAL @2.3.99.1: fatal error: 'filesystem' file not found
-------------------------+----------------------
  Reporter:  ryandesign  |      Owner:  Veence
      Type:  defect      |     Status:  assigned
  Priority:  Normal      |  Milestone:
 Component:  ports       |    Version:  2.7.2
Resolution:              |   Keywords:
      Port:  PDAL        |
-------------------------+----------------------

Comment (by mascguy):

 Replying to [comment:9 kencu]:
 > works.:
 >
 > {{{
 > PortGroup           legacysupport 1.1
 >
 > legacysupport.newest_darwin_requires_legacy 18
 > legacysupport.use_mp_libcxx yes
 > }}}

 I can confirm this works for 10.13 as well, so I'll push the change.

 We can always revert if it causes issues. But thus far, `macports-libcxx`
 has worked beautifully. So I don't anticipate any issues.

-- 
Ticket URL: <https://trac.macports.org/ticket/64869#comment:11>
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