My laptop doesn’t recognize Wi-Fi LAN Drivers

Summary A routine Windows cumulative update introduced a regression in the Intel Wi-Fi driver compatibility (specifically involving the driver version iwnet64.sys), causing the wireless adapter to fail initialization and appear “Not present” in Device Manager. This resulted in immediate loss of network connectivity for affected users. The issue was resolved by manually installing the specific … Read more

Should “global consistency” be enabled by default in PolarDB? What are the trade-offs?

Summary The question of whether global consistency should be enabled by default in PolarDB for production systems is complex and depends on several factors, including latency, throughput, and read/write splitting behavior. Enabling global consistency can provide strong consistency across all nodes, but it may come at the cost of increased latency and decreased throughput. Root … Read more

How to resolve “error whilst” resolving message after updating library?

Summary This incident describes a common Node.js dependency resolution failure—specifically an ERESOLVE conflict—occurring after attempting to update libraries in a React Native project. The error specifically highlights a peer dependency mismatch between @react-navigation/drawer and @react-navigation/native. Problem: npm 7+ enforces strict peer dependency checking. Conflict: The installed version of @react-navigation/native (v6.1.18) does not satisfy the peer … Read more

Pandas rename() not working on MultiIndex columns with tuples

Summary The user reported a problem where pandas.DataFrame.rename(columns=…) fails to rename MultiIndex columns defined by tuples. The root cause is that pandas rename() does not support a tuple-based mapping for MultiIndex columns in the dictionary format. While pandas 2.2.0 introduced support for passing a callable to the columns argument for MultiIndex renaming, passing a dictionary … Read more

Declaring member variables in a class interface header file

Summary The question revolves around the declaration of member variables in a C++ class interface header file. Key concepts include understanding the difference between declaration and initialization, as well as the proper use of references and pointers as class members. The provided example includes a class OCR with members such as a reference to an … Read more

dangerous relocation: unsupported relocation (R_ARM_SBREL32)

Summary The postmortem analyzes a compilation failure on an ARM Cortex-M0+ project, where the linker flags a relocation type R_ARM_SBREL32 as “dangerous” and “unsupported.” The issue occurs because the developer used the -frwpi flag, which stands for Read-Only Write-Once Pointer Initialization. This flag is designed for a specific code model that requires the linker to … Read more

Theoretical results on performance bounds for virtual machines and bytecode interpreters

Summary This postmortem analyzes the theoretical performance bounds of virtual machines (VMs) and bytecode interpreters relative to native instruction execution. The core finding is that while interpreters introduce unavoidable overhead, modern techniques like Just-In-Time (JIT) compilation and efficient dispatch methods narrow the gap significantly. The “2x/3x slowdown” observed in WASM is not a universal theoretical … Read more

Custom SpinLock implementation

Summary A developer attempted to implement a custom SpinLock in Rust based on Mara Bos’s book to protect shared mutable state across threads. The code resulted in memory safety issues (segmentation faults or undefined behavior) because the raw SpinLock was used to guard an UnsafeCell containing a String without adhering to Rust’s strict concurrency safety … Read more

Projecting a Text onto a wave Like Loft Prior tobextrude it

Summary A user attempted to project text onto a complex, wave-like surface generated in Grasshopper (a Rhino plugin) but encountered difficulties using the Surface Morph component. The core issue was attempting to use a single Loft surface to describe a compound geometry formed by pipes and connecting bows. Surface Morph requires a valid U-V coordinate … Read more