Default arrow to release if no build-type is otherwise specified

Author: jleibs

rerun_cpp/CMakeLists.txt

@@ -159,6 +159,12 @@ if(RERUN_DOWNLOAD_AND_BUILD_ARROW)
         set(DARROW_CXXFLAGS "")
     endif()
 
+    if(NOT CMAKE_BUILD_TYPE)
+        set(ARROW_CMAKE_BUILD_TYPE Release)
+    else()
+        set(ARROW_CMAKE_BUILD_TYPE ${CMAKE_BUILD_TYPE})
+    endif()
+
     ExternalProject_Add(
         arrow_cpp
         PREFIX ${ARROW_DOWNLOAD_PATH}
@@ -179,7 +185,7 @@ if(RERUN_DOWNLOAD_AND_BUILD_ARROW)
         -DARROW_USE_TSAN=OFF
         -DARROW_USE_UBSAN=OFF
         -DBOOST_SOURCE=BUNDLED
-        -DCMAKE_BUILD_TYPE=${CMAKE_BUILD_TYPE}
+        -DCMAKE_BUILD_TYPE=${ARROW_CMAKE_BUILD_TYPE}
         -DCMAKE_INSTALL_PREFIX=${ARROW_DOWNLOAD_PATH}
         -Dxsimd_SOURCE=BUNDLED
         SOURCE_SUBDIR cpp