build: kindly ask python not to polute src/

Type: make
Change-Id: I1ec82e0f3c19dee79f942996339240c73d4e380c
Signed-off-by: Damjan Marion <damarion@cisco.com>
diff --git a/src/cmake/api.cmake b/src/cmake/api.cmake
index 007a906..831c2b1 100644
--- a/src/cmake/api.cmake
+++ b/src/cmake/api.cmake
@@ -38,7 +38,7 @@
   add_custom_command (
     OUTPUT ${OUTPUT_HEADERS}
     COMMAND mkdir -p ${output_dir}
-    COMMAND ${VPP_APIGEN}
+    COMMAND ${PYENV} ${VPP_APIGEN}
     ARGS ${includedir} --includedir ${CMAKE_SOURCE_DIR} --input ${CMAKE_CURRENT_SOURCE_DIR}/${file} --outputdir ${output_dir} --output ${output_name}
     DEPENDS ${VPP_APIGEN} ${CMAKE_CURRENT_SOURCE_DIR}/${file}
     COMMENT "Generating API header ${output_name}"
@@ -63,7 +63,7 @@
   endif()
   add_custom_command (OUTPUT ${output_name}
     COMMAND mkdir -p ${output_dir}
-    COMMAND ${VPP_APIGEN}
+    COMMAND ${PYENV} ${VPP_APIGEN}
     ARGS ${includedir} --includedir ${CMAKE_SOURCE_DIR} --input ${CMAKE_CURRENT_SOURCE_DIR}/${file} JSON --output ${output_name}
     DEPENDS ${VPP_APIGEN} ${CMAKE_CURRENT_SOURCE_DIR}/${file}
     COMMENT "Generating API header ${output_name}"
@@ -94,7 +94,7 @@
   add_custom_command(
     OUTPUT ${output_name}
     WORKING_DIRECTORY ${VPP_BINARY_DIR}/vpp-api/vapi
-    COMMAND ${VPP_VAPI_C_GEN}
+    COMMAND ${PYENV} ${VPP_VAPI_C_GEN}
     ARGS --remove-path ${input}
     DEPENDS ${input} ${VPP_VAPI_C_GEN_DEPENDS}
     COMMENT "Generating VAPI C header ${output_name}"
@@ -121,7 +121,7 @@
   add_custom_command(
     OUTPUT ${output_name}
     WORKING_DIRECTORY ${VPP_BINARY_DIR}/vpp-api/vapi
-    COMMAND ${VPP_VAPI_CPP_GEN}
+    COMMAND ${PYENV} ${VPP_VAPI_CPP_GEN}
     ARGS --gen-h-prefix=vapi --remove-path ${input}
     DEPENDS ${input} ${VPP_VAPI_CPP_GEN_DEPENDS}
     COMMENT "Generating VAPI C++ header ${output_name}"