[MacPorts] #61525: py38-scikit-learn fails to build on macOS 11 Big Sur

[MacPorts]

#61525: py38-scikit-learn fails to build on macOS 11 Big Sur
------------------------------+----------------------
  Reporter:  smeingast        |      Owner:  stromnov
      Type:  defect           |     Status:  assigned
  Priority:  Normal           |  Milestone:
 Component:  ports            |    Version:  2.6.4
Resolution:                   |   Keywords:
      Port:  py-scikit-learn  |
------------------------------+----------------------

Comment (by cjones051073):

 The port is using macports clang 9.0 compiler to build (not clear exactly
 why to me ?) but setting the deployment target to 11.0, which this older
 version of the compiler does not understand

 {{{
 :info:build clang: error: invalid version number in
 'MACOSX_DEPLOYMENT_TARGET=11.0'
 }}}

 The solution is to either move to a new compiler that knows about the 11.0
 target, or set the target for this build to 11.6, e.g. something like

 {{{
  if { ${os.major} == 20 } {
     macosx_deployment_target 10.16
 }
 }}}

 maybe with additional checks to only do that if macports clang 9.0 (or 10)
 is used. clang 11 (coming soon) might well understand 11.0.

-- 
Ticket URL: <https://trac.macports.org/ticket/61525#comment:2>
MacPorts <https://www.macports.org/>
Ports system for macOS