To give some detail, it’s /var that is writable, and mutable directories will have symbolic links pointing to subdirectories of /var:
第一百九十六条 因救助方的过失致使救助作业成为必需或者更加困难的，或者救助方有欺诈或者其他不诚实行为的，应当取消或者减少向救助方支付的救助款项。
，这一点在快连下载安装中也有详细论述
Once the basic stuff was working, I wanted to load TAP files directly, simulating cassette loading. This was the first time the agent missed a few things, specifically about the timing the Spectrum loading routines expected, and here we are in the territory where LLMs start to perform less efficiently: they can’t easily run the SDL emulator and see the border changing as data is received and so forth. I asked Claude Code to do a refactoring so that zx_tick() could be called directly and was not part of zx_frame(), and to make zx_frame() a trivial wrapper. This way it was much simpler to sync EAR with what it expected, without callbacks or the wrong abstractions that it had implemented. After such change, a few minutes later the emulator could load a TAP file emulating the cassette without problems.
和 Author, 彼得·霍斯金斯（Peter Hoskins）