The Nix Hour #1 [nixcon, reviewing a PR, debugging and tracing Nix evaluation]

«Час Никса» - это еженедельная импровизированная лекция о Nix в стиле вопросов и ответов для начинающих, на которой вы можете задать свои вопросы, а мы ответим на них с подробным описанием контекста, примерами, альтернативами, компромиссами и смежными темами. 0:00 Initial look at PR 186314 2:35 Markdown documentation in NixOS options 3:05 Systemd unit types and index manpage 4:14 Another look at the PR 6:04 Pattern for handling enumerations 8:03 lib.partition for splitting a list of values into two 10:05 lib.groupBy for splitting a list of values into more subsets 12:30 Following lib.groupBy with a lib.mapAttrs 13:22 Trying to figure out the evaluation error without reading the error message 14:53 Adding tracing using lib.debug.traceSeq 16:49 nix-instantiate flags relating to lazy/strict evaluation 17:56 Realizing the problem, missing --strict with --json 18:20 nix eval strictness 19:09 Setup to demonstrate problem with nix eval strictness compared to nix-instantiate 20:24 nix repl derivation output 22:00 Demonstrating problem with nix eval strictness compared to nix-instantiate 24:12 Using the GitHub CLI to check out PR 186314 25:13 Trying to do a «quick» refactoring using lib.groupBy and the enum handling pattern from earlier 32:27 How to find documentation for nixpkgs library functions 33:49 Except for Nix builtin functions re-exported from the nixpkgs library 34:38 How to find documentation for Nix builtin functions 35:16 nix repl :doc command for Nix builtin function...