Don't set march=native or other c flags under cibuildwheel or conda

Author: ihnorton

src/CMakeLists.txt

@@ -102,25 +102,24 @@ endif()
 # Control compiler-specific flags.
 include(CompilerFlags)
 
-
-if (CMAKE_OSX_ARCHITECTURES STREQUAL arm64 OR CMAKE_SYSTEM_PROCESSOR MATCHES "^aarch64" OR CMAKE_SYSTEM_PROCESSOR MATCHES "^arm")
-    set(CMAKE_CXX_FLAGS_DEBUG "-O0 -g -fno-elide-constructors ${FCONCEPTS_DIAGNOSTICS_DEPTH} " CACHE STRING "" FORCE)
-    set(CMAKE_CXX_FLAGS_RELEASE "-Ofast -DNDEBUG " CACHE STRING "" FORCE)
-#    set(CMAKE_CXX_FLAGS_RELWITHDEBINFO "-Ofast -g -DNDEBUG" CACHE STRING "" FORCE)
-    set(CMAKE_CXX_FLAGS_RELWITHDEBINFO "-Ofast -g -UNDEBUG" CACHE STRING "" FORCE)
-    set(CMAKE_CXX_FLAGS_MINSIZEREL "-Os -DNDEBUG " CACHE STRING "" FORCE)
-elseif(MSVC)
-    set(CMAKE_CXX_FLAGS_DEBUG "/Od /Zi /EHsc /RTC1" CACHE STRING "" FORCE)
-    set(CMAKE_CXX_FLAGS_RELEASE "/O2" CACHE STRING "" FORCE)
-    set(CMAKE_CXX_FLAGS_RELWITHDEBINFO "/O2 /Zi" CACHE STRING "" FORCE)
-    set(CMAKE_CXX_FLAGS_MINSIZEREL "/O1" CACHE STRING "" FORCE)
-    add_compile_definitions("$<$<NOT:$<CONFIG:Debug>>:NDEBUG>")
-else()
-    set(CMAKE_CXX_FLAGS_DEBUG "-O0 -g -fno-elide-constructors ${FCONCEPTS_DIAGNOSTICS_DEPTH} " CACHE STRING "" FORCE)
-    set(CMAKE_CXX_FLAGS_RELEASE "-Ofast -march=native -DNDEBUG " CACHE STRING "" FORCE)
-#    set(CMAKE_CXX_FLAGS_RELWITHDEBINFO "-Ofast -g -march=native -DNDEBUG" CACHE STRING "" FORCE)
-    set(CMAKE_CXX_FLAGS_RELWITHDEBINFO "-Ofast -g -march=native -UNDEBUG" CACHE STRING "" FORCE)
-    set(CMAKE_CXX_FLAGS_MINSIZEREL "-Os -march=native -DNDEBUG " CACHE STRING "" FORCE)
+if (NOT $ENV{CIBUILDWHEEL} EQUAL 1 AND NOT $ENV{CONDA_BUILD} EQUAL 1)
+  if(MSVC)
+      set(CMAKE_CXX_FLAGS_DEBUG "/Od /Zi /EHsc /RTC1" CACHE STRING "" FORCE)
+      set(CMAKE_CXX_FLAGS_RELEASE "/O2" CACHE STRING "" FORCE)
+      set(CMAKE_CXX_FLAGS_RELWITHDEBINFO "/O2 /Zi" CACHE STRING "" FORCE)
+      set(CMAKE_CXX_FLAGS_MINSIZEREL "/O1" CACHE STRING "" FORCE)
+      add_compile_definitions("$<$<NOT:$<CONFIG:Debug>>:NDEBUG>")
+  elseif (CMAKE_OSX_ARCHITECTURES STREQUAL arm64 OR CMAKE_SYSTEM_PROCESSOR MATCHES "^aarch64" OR CMAKE_SYSTEM_PROCESSOR MATCHES "^arm")
+      set(CMAKE_CXX_FLAGS_DEBUG "-O0 -g -fno-elide-constructors ${FCONCEPTS_DIAGNOSTICS_DEPTH} " CACHE STRING "" FORCE)
+      set(CMAKE_CXX_FLAGS_RELEASE "-Ofast -DNDEBUG " CACHE STRING "" FORCE)
+      set(CMAKE_CXX_FLAGS_RELWITHDEBINFO "-Ofast -g -UNDEBUG" CACHE STRING "" FORCE)
+      set(CMAKE_CXX_FLAGS_MINSIZEREL "-Os -DNDEBUG " CACHE STRING "" FORCE)
+  else()
+      set(CMAKE_CXX_FLAGS_DEBUG "-O0 -g -fno-elide-constructors ${FCONCEPTS_DIAGNOSTICS_DEPTH} " CACHE STRING "" FORCE)
+      set(CMAKE_CXX_FLAGS_RELEASE "-Ofast -march=native -DNDEBUG " CACHE STRING "" FORCE)
+      set(CMAKE_CXX_FLAGS_RELWITHDEBINFO "-Ofast -g -march=native -UNDEBUG" CACHE STRING "" FORCE)
+      set(CMAKE_CXX_FLAGS_MINSIZEREL "-Os -march=native -DNDEBUG " CACHE STRING "" FORCE)
+  endif()
 endif()
 
 # Default to Release build