[MacPorts] #56941: cmake @3.12.0_0 and gcc7 @7.3.0_3 don't work well together

[MacPorts]

#56941: cmake @3.12.0_0 and gcc7 @7.3.0_3 don't work well together
-------------------------+-----------------------
  Reporter:  iqgrande    |      Owner:  michaelld
      Type:  defect      |     Status:  assigned
  Priority:  Normal      |  Milestone:
 Component:  ports       |    Version:  2.5.3
Resolution:              |   Keywords:
      Port:  cmake, gcc  |
-------------------------+-----------------------

Comment (by michaelld):

 Can you try the following from the "macports_build_issues" directory:
 {{{
 rm -rf CMakeCache.txt CMakeFiles
 mkdir build
 cd build
 CC=/opt/local/bin/gcc-mp-7 CXX=/opt/local/bin/g++-mp-7 cmake ..
 }}}
 Here's what my system returns:
 {{{
 % CC=/opt/local/bin/gcc-mp-7 CXX=/opt/local/bin/g++-mp-7 cmake  ..
 -- The C compiler identification is GNU 7.3.0
 -- The CXX compiler identification is GNU 7.3.0
 -- Checking whether C compiler has -isysroot
 -- Checking whether C compiler has -isysroot - yes
 -- Checking whether C compiler supports OSX deployment target flag
 -- Checking whether C compiler supports OSX deployment target flag - yes
 -- Check for working C compiler: /opt/local/bin/gcc-mp-7
 -- Check for working C compiler: /opt/local/bin/gcc-mp-7 -- works
 -- Detecting C compiler ABI info
 -- Detecting C compiler ABI info - done
 -- Detecting C compile features
 -- Detecting C compile features - done
 -- Checking whether CXX compiler has -isysroot
 -- Checking whether CXX compiler has -isysroot - yes
 -- Checking whether CXX compiler supports OSX deployment target flag
 -- Checking whether CXX compiler supports OSX deployment target flag - yes
 -- Check for working CXX compiler: /opt/local/bin/g++-mp-7
 -- Check for working CXX compiler: /opt/local/bin/g++-mp-7 -- works
 -- Detecting CXX compiler ABI info
 -- Detecting CXX compiler ABI info - done
 -- Detecting CXX compile features
 -- Detecting CXX compile features - done
 -- Configuring done
 -- Generating done
 -- Build files have been written to:
 /Users/mlk/Desktop/TMP/macports_build_issues/build
 }}}

-- 
Ticket URL: <https://trac.macports.org/ticket/56941#comment:8>
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