Force MacOS compiler, don't specify libs

Author: weshinsley

.github/workflows/macos_distribution_check.yml

@@ -20,7 +20,7 @@ jobs:
     - name: build
       run: |
         mkdir build && cd build
-        cmake -DUSE_OPENMP=OFF ..
+        cmake ..
         make
     - name: unit tests
       run: |

CMakeLists.txt

@@ -3,6 +3,13 @@
 # CMake setup
 cmake_minimum_required (VERSION 3.11)
 
+# Force Mac OS to use a compiler that can compile multi-threaded.
+
+if(APPLE)
+  set(CMAKE_C_COMPILER "/usr/local/opt/llvm/bin/clang")
+  set(CMAKE_CXX_COMPILER "/usr/local/opt/llvm/bin/clang++")
+endif()
+
 # Project initialisation
 project("CovidSim")
 

tests/CMakeLists.txt

@@ -3,14 +3,8 @@
 # The "test-accept" target runs all tests and accepts their output.
 add_custom_target("test-accept")
 
-if(APPLE)
-  set(END_THREAD 1)
-else()
-  set(END_THREAD 2)
-endif()
-
 function(add_integration_test TESTNAME INPUT OUTPUT_ROOT POPFILE R)
-  foreach(j RANGE 1 ${END_THREAD})
+  foreach(j RANGE 1 2)
     set(test_name "${TESTNAME}-j${j}")
     set(accept_name "${test_name}-accept")
     add_test(NAME "${test_name}"