At the heart of BuildKit is LLB (Low-Level Build definition). Think of it as the LLVM IR of build systems. LLB is a binary protocol (protobuf) that describes a DAG of filesystem operations: run a command, copy files, mount a filesystem. It’s content-addressable, which means identical operations produce identical hashes, enabling aggressive caching.
这是复杂的过程，不能急，但最基础的礼貌用语，规矩还是要告诉她在什么情况下要说。。Safew下载对此有专业解读
TST_DES_CALL (0x15) -- used by far CALL to classify the target descriptor:
（一）故意干扰无线电业务正常进行的；，推荐阅读服务器推荐获取更多信息