[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
 Keywords:            |       Port:  cmake, gcc
----------------------+------------------------
 Greetings:

 I am unable to use MacPorts CMake with MacPorts GCC compilers. My error is
 below along with a simple reproducer. I have attached my source and output
 from the command below in the attached tarball. I am unsure as to which
 port has the issue(s) so I included the CMake port maintainer as the owner
 since there is no GCC port maintainer. Also, I tested this with every
 gcc-* item within my /opt/local/bin (e.g., gcc-mp-7, gcc-ar-mp-7, gcc-
 ranlib-mp-7) for both gcc7 and gcc8 ports. The CMake Port does appear to
 use the Apple LLVM compilers fine. Thank you for your help with this.


 =`main.c`=
 {{{
 #include <stdio.h>

 int main()
 {
     printf("Hello world.\n");
     return 0;
 }
 }}}

 =`CMakeLists.txt`=
 {{{
 cmake_minimum_required (VERSION 2.6)
 project (test)

 add_executable (test main.c)
 }}}

 =Errors=
 {{{
 $ cmake -DCMAKE_C_COMPILER=/opt/local/bin/gcc-mp-7 .
 -- The C compiler identification is unknown
 -- The CXX compiler identification is unknown
 -- Check for working C compiler: /opt/local/bin/gcc-mp-7
 -- Check for working C compiler: /opt/local/bin/gcc-mp-7 -- broken
 CMake Error at
 /opt/local/share/cmake-3.12/Modules/CMakeTestCCompiler.cmake:52 (message):
   The C compiler

     "/opt/local/bin/gcc-mp-7"

   is not able to compile a simple test program.

   It fails with the following output:

     Change Dir: /path/to/macports_build_issues/CMakeFiles/CMakeTmp

     Run Build Command:"/opt/local/bin/gmake" "cmTC_2bb49/fast"
     /opt/local/bin/gmake -f CMakeFiles/cmTC_2bb49.dir/build.make
 CMakeFiles/cmTC_2bb49.dir/build
     gmake[1]: Entering directory
 '/path/to/macports_build_issues/CMakeFiles/CMakeTmp'
     Building C object CMakeFiles/cmTC_2bb49.dir/testCCompiler.c.o
     /opt/local/bin/gcc-mp-7    -o
 CMakeFiles/cmTC_2bb49.dir/testCCompiler.c.o   -c
 /path/to/macports_build_issues/CMakeFiles/CMakeTmp/testCCompiler.c
     FATAL:/opt/local/bin/../libexec/as/x86_64/as: I don't understand 'm'
 flag!
     gmake[1]: *** [CMakeFiles/cmTC_2bb49.dir/build.make:66:
 CMakeFiles/cmTC_2bb49.dir/testCCompiler.c.o] Error 1
     gmake[1]: Leaving directory
 '/path/to/macports_build_issues/CMakeFiles/CMakeTmp'
     gmake: *** [Makefile:121: cmTC_2bb49/fast] Error 2




   CMake will not be able to correctly generate this project.
 Call Stack (most recent call first):
   CMakeLists.txt:2 (project)


 -- Configuring incomplete, errors occurred!
 See also "/path/to/macports_build_issues/CMakeFiles/CMakeOutput.log".
 See also "/path/to/macports_build_issues/CMakeFiles/CMakeError.log".
 }}}

 Kind regards,
 Anthony

-- 
Ticket URL: <https://trac.macports.org/ticket/56941>
MacPorts <https://www.macports.org/>
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