Use CMake's standard way to find Python.

Rather than have the python literal string, use CMake's find_package
to find actual python executable. This is more useful if you have
both Python 2 and 3 installed. CMake currently only supports python 2
and so will automatically find that version

CMakeLists.txt

@@ -5,6 +5,8 @@ project(node)
 # options
 #
 
+find_package(PythonInterp 2 REQUIRED)
+
 option(SHARED_V8 "use system shared V8 library")
 option(SHARED_LIBEV "use system shared libev library")
 option(SHARED_CARES "use system shared c-ares library")

cmake/node_build.cmake

@@ -4,7 +4,7 @@
 
 add_custom_command(
   OUTPUT ${PROJECT_BINARY_DIR}/src/node_natives.h
-  COMMAND tools/js2c.py ${PROJECT_BINARY_DIR}/src/node_natives.h ${js2c_files}
+  COMMAND ${PYTHON_EXECUTABLE} tools/js2c.py ${PROJECT_BINARY_DIR}/src/node_natives.h ${js2c_files}
   DEPENDS ${js2c_files})
 
 set(node_extra_src "src/platform_${node_platform}.cc")

cmake/v8_build.cmake

@@ -43,7 +43,7 @@ if(NOT SHARED_V8)
       URL ${PROJECT_SOURCE_DIR}/deps/v8
       
       BUILD_IN_SOURCE True
-      BUILD_COMMAND sh -c "${PROJECT_BINARY_DIR}/tools/scons/scons.py library=static visibility=default ${v8snapshot} mode=${v8mode} verbose=on arch=${v8arch} -j ${parallel_jobs}"
+      BUILD_COMMAND ${PYTHON_EXECUTABLE} ${PROJECT_BINARY_DIR}/tools/scons/scons.py library=static visibility=default ${v8snapshot} mode=${v8mode} verbose=on arch=${v8arch} -j ${parallel_jobs}
       
       SOURCE_DIR ${PROJECT_BINARY_DIR}/deps/v8
       # ignore this stuff, it's not needed for building v8 but ExternalProject
@@ -74,7 +74,7 @@ if(NOT SHARED_V8)
 
     add_custom_command(
       OUTPUT ${PROJECT_BINARY_DIR}/deps/v8/${v8_fn}
-      COMMAND ${PROJECT_BINARY_DIR}/tools/scons/scons.py library=static visibility=default ${v8snapshot} mode=${v8mode} verbose=on arch=${v8arch} -j ${parallel_jobs}
+      COMMAND ${PYTHON_EXECUTABLE} ${PROJECT_BINARY_DIR}/tools/scons/scons.py library=static visibility=default ${v8snapshot} mode=${v8mode} verbose=on arch=${v8arch} -j ${parallel_jobs}
       WORKING_DIRECTORY ${PROJECT_BINARY_DIR}/deps/v8/
       DEPENDS ${v8_sources_dest}
     )