Why does “make” insert a prefix folder into the middle of a stem, but not into the beginning?

Summary The issue arises when using GNU Make’s pattern rules with directory structures. The stem ($*) in a pattern rule like deps/%.d is expanded based on the target’s basename, not its full path. This leads to unexpected directory prefixes when the target is in a subdirectory. Root Cause Pattern Rule Expansion: GNU Make’s pattern rules … Read more

Cross-compiling for arm64 using visual studio and WSL2 is generating x64 binary

Summary Cross-compiling for ARM64 using Visual Studio 2022 and WSL2 resulted in x64 binaries instead of the expected ARM64 output. Despite correct configurations and toolchains, the build system defaulted to the host architecture, ignoring the target platform. Root Cause The root cause was Visual Studio’s default behavior of using the host toolchain (x64) instead of … Read more

wkhtmltopdf repeated table headers overlap content when a single table row spans multiple pages

Summary This postmortem analyzes a wkhtmltopdf table‑rendering defect where repeated table headers overlap content when a single table row spans multiple pages. Although the HTML renders correctly in browsers, wkhtmltopdf’s legacy layout engine fails to reserve vertical space for the repeated header, causing visual corruption and truncated content. Root Cause The underlying issue is a … Read more

Different between tsvector and tsquery

Summary The difference between tsvector and tsquery in PostgreSQL can be confusing, even after reading the documentation. In essence, tsvector is used to normalize and optimize text data for searching, while tsquery is used to specify the search terms. Understanding the distinction between these two data types is crucial for effective text search in PostgreSQL. … Read more

How to Achieve Data Downsampling Similar to the M4 Function in Apache IoTDB’s Table Model?

Summary This incident analyzes why Apache IoTDB’s M4 downsampling function works in the Tree Model but fails in the Table Model, and how engineers can still achieve equivalent results using supported SQL constructs. The core issue is a feature gap: the Table Model does not yet implement the M4 aggregation function. Root Cause The failure … Read more

How to properly retrieve context in an OpenAI Realtime conversation using response.create

Summary A misconfigured OpenAI Realtime response.create call caused the model to ignore the custom instructions and instead continue the default assistant turn. The system never received the prior conversation context because the request did not explicitly reference the correct conversation state, leading to repeated assistant messages instead of the expected summary/sentiment output. Root Cause conversation: … Read more

How many way to implement Audio Streaming

Summary This postmortem analyzes a common failure mode in early-stage “music platform” projects: oversimplifying audio streaming architecture and assuming that HLS is the only viable method. The incident stems from incomplete understanding of streaming models, delivery protocols, and scalability constraints. Root Cause The root cause was limited awareness of the full spectrum of audio‑streaming approaches, … Read more

TCPIP connection issue at the port in azure databricks

Summary A misconfigured network access path between Azure Databricks and Azure SQL Database caused the TCP/IP connection failure. Although authentication and SQL objects were correctly created, the SQL server was not reachable from the Databricks workspace due to firewall, VNet, or region‑level connectivity restrictions. Root Cause The failure stems from Azure SQL Database firewall rules … Read more

YouTube Transcript API returns “Could not retrieve a transcript” error – IP blocking or rate limiting?

Summary YouTube’s Transcript API returned “Could not retrieve a transcript” errors after ~40 requests, blocking access to all videos. The issue persisted despite using a residential ISP, indicating IP-based rate limiting or blocking by YouTube. Root Cause Rate limiting enforcement: YouTube’s API imposes unpublished rate limits to prevent abuse. IP-based blocking: Excessive requests from a … Read more

How do I return the PID of an osascript call from within a function (or how do I create a persistent notification I can kill later in the script)?

Summary This incident revolves around a Bash subshell side effect: when you wrap a function call in $(…), the function executes in a subshell, and any variables set inside it—including your captured PID—are lost when the subshell exits. The result is a mysteriously empty PID variable, even though the logic appears correct. Root Cause The … Read more