[MacPorts] #67314: R: do we need sysroot to be detected on systems without xcrun?

[MacPorts]

#67314: R: do we need sysroot to be detected on systems without xcrun?
---------------------------+-----------------------------------------
  Reporter:  barracuda156  |      Owner:  kjellpk
      Type:  defect        |     Status:  assigned
  Priority:  Normal        |  Milestone:
 Component:  ports         |    Version:  2.8.1
Resolution:                |   Keywords:  tiger, leopard, snowleopard
      Port:  R             |
---------------------------+-----------------------------------------

Comment (by ryandesign):

 Something in the build system is evidently running `xcrun --show-sdk-
 path`. That doesn't work on old OS versions like Snow Leopard however:

 {{{
 $ xcrun --show-sdk-path
 xcrun: error: unrecognized option: --show-sdk-path

 usage:
 xcrun [-verbose] [-no-cache] [-kill-cache] [-sdk <sdkroot>] [-log] [-run]
 <utility> [utility argument(s) ...]
 xcrun [-verbose] [-no-cache] [-kill-cache] [-sdk <sdkroot>] -find
 <utility>
 <tool> [tool arguments ...]
 $ echo $?
 64
 }}}

 And as Ken said we would like for the build system not to do that.

-- 
Ticket URL: <https://trac.macports.org/ticket/67314#comment:3>
MacPorts <https://www.macports.org/>
Ports system for macOS