<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def build(self, tool):
 """build the project"""


        tools = self._validate_tools(tool)
        if tools == -1:
            return -1

        result = 0

        for build_tool in tools:
            builder = ToolsSupported().get_tool(build_tool)
            # None is an error
            if builder is None:
                logger.debug("Tool: %s was not found" % builder)
                result = -1
                continue

            logger.debug("Building for tool: %s", build_tool)
            logger.debug(self.generated_files)
            if builder(self.generated_files[build_tool], self.settings).build_project() == -1:
                # if one fails, set to -1 to report
                result = -1
        return result