working on race condition for grpc build

SConstruct

@@ -19,7 +19,7 @@ env = Environment(
 env['PROTOCCPPOUTDIR']  = env['TURBO_HOME'] + "/turbo-rpc"
 env['PROTOCGRPCOUTDIR'] = env['TURBO_HOME'] + "/turbo-rpc"
 env['PROTOCPROTOPATH'] =  '.'
-env['PROTOCCOM']        = '$PROTOC ${["-I%s"%x for x in PROTOCPROTOPATH]} $PROTOCFLAGS --proto_path=$PWD --cpp_out='+env['TURBO_HOME']+' --grpc_out='+env['TURBO_HOME']+' --plugin=protoc-gen-grpc=`which grpc_cpp_plugin` ${SOURCES} '
+env['PROTOCCOM']        = '$PROTOC ${["-I%s"%x for x in PROTOCPROTOPATH]} $PROTOCFLAGS --proto_path=$PWD --cpp_out='+env['TURBO_HOME']+' --grpc_out='+env['TURBO_HOME']+' --plugin=protoc-gen-grpc=`which grpc_cpp_plugin` ${SOURCES} ; echo protoc complete'
 
 Export('env')
 

tools/protoc.py

@@ -57,10 +57,10 @@ def generate(env):
         bld = ProtocBuilder
         env['BUILDERS']['protoc'] = bld
 
-    env['PROTOC']        = 'pwd; ' + (env.Detect(protocs) or 'protoc')
+    env['PROTOC']        = 'pwd; ' + (env.Detect(protocs) or 'protoc') 
     env['PROTOCFLAGS']   = SCons.Util.CLVar('')
     env['PROTOCPROTOPATH'] = SCons.Util.CLVar('')
-    env['PROTOCCOM']     = '$PROTOC ${["-I%s"%x for x in PROTOCPROTOPATH]} $PROTOCFLAGS --cpp_out=$PROTOCCPPOUTFLAGS$PROTOCOUTDIR ${PROTOCPYTHONOUTDIR and ("--python_out="+PROTOCPYTHONOUTDIR) or ""} ${PROTOCFDSOUT and ("-o"+PROTOCFDSOUT) or ""} ${SOURCES}'
+    env['PROTOCCOM']     = '$PROTOC ${["-I%s"%x for x in PROTOCPROTOPATH]} $PROTOCFLAGS --cpp_out=$PROTOCCPPOUTFLAGS$PROTOCOUTDIR ${PROTOCPYTHONOUTDIR and ("--python_out="+PROTOCPYTHONOUTDIR) or ""} ${PROTOCFDSOUT and ("-o"+PROTOCFDSOUT) or ""} ${SOURCES}; echo protoc complete'
     env['PROTOCOUTDIR'] = '${SOURCE.dir}'
     env['PROTOCPYTHONOUTDIR'] = "python"
     env['PROTOCSRCSUFFIX']  = '.proto'