Notes

Migrating a Postgres database between servers

A quick rundown of the process so future me can have an easier time

GPT-5 seems to forget things well within its context window

An instance of LLMs seemingly not being able to utilize their context window effectively

Copying Nix Flake inputs to a different machine

Simple one-liner to avoid re-downloading inputs on a different machine on your LAN

Changing the locale set on a maching running Postgres

I keep rediscovering that Postgres uses the system locale and timezone database, despite having read other people’s woes. I changed the locale in my NixOS configuration from en_US to en_GB to appease the spell checker on my desktop. When I deployed this updated configuration to one of my servers, all my services immediately fell over. I had the sense to look at journalctl right away which made it very apparent what the problem was: ...

Welcome to Notes

New section woo! This is mostly going to be used for relatively smaller things that I don’t find worthy of a blogpost but are a bit awkward to fit into a toot. Over time I plan to backfill this with the contents of my Obsidian Vault’s “TIL” folder and then just use this public listing for the purpose, since it’s equally accessible to me via the excellent Sveltia CMS.

Adding boarding passes to Google Wallet

Google Wallet lets you add passes via image, so rather than try to share a PDF with it you can take a screenshot and share that to the app instead. “Google AI” does the rest.

Interactive reverts in Git

Git has the capability to revert only specific hunks of a commit using the git checkout --patch command. To revert the changes to file example.md made in commit 0xDEADBEEF, you would run git checkout --patch 0xDEADBEEF^ example.md and Git will open up the interactive diff editor so you can select which reverts you want to apply to your index.

Debugging issues with provisioning certificates from Let's Encrypt

Let’s Debug provides a way to test if your domain is set up to correctly answer Let’s Encrypt challenges.

Oracle Cloud's restrictive default network policy

Oracle cloud doesn’t enable any ports other than SSH by default, which somehow doesn’t affect any Tailscale services but breaks the ability to negotiate a TLS certificate over ports 80 and 443.

Cargo failing at gitignore-d files while publishing

Finally managed to find a workaround for the Rust problem I was having with cargo publish picking up files from my gitignore-d .direnv directory and complaining about them being uncommitted. This was the result of cascading surprises: setting package.includes causes gitignore to no longer be considered, and "README.md" in package.includes actually works like "**/README.md"’ and picks up the READMEs from the repositories in .direnv/flake-inputs/. Upstream issue: https://github.com/rust-lang/cargo/issues/12294#issuecomment-2171044946