devenv-machines-plan(1)

📦 version 2.4.0, in nixpkgs unstable

💅 devenv-machines-plan — the group-chat guide

okay so this is devenv-machines-plan(1), the little command that builds you a whole fleet deployment plan and saves it so you can actually look it over before anything scary happens. bestie, this is the "let me screenshot it first" of deployment. 🫶

✨ NAME ✨

devenv-machines-plan — build and save a fleet deployment plan for review. that's it, that's the vibe. 🎀

🌸 SYNOPSIS 🌸

devenv machines plan [--json] [--user-config] [--from]
[-o|--override-input] [-O|--option] [-j|--max-jobs] [-u|--cores]
[-s|--system] [-i|--impure] [--no-impure] [--offline] [--nix-option]
[--nix-debugger] [-c|--clean] [-P|--profile] [--reload] [--no-reload]
[--shell] [--eval-cache] [--no-eval-cache] [--refresh-eval-cache]
[--refresh-task-cache] [--secretspec-provider] [--secretspec-profile]
[--trace-to] [-v|--verbose] [-q|--quiet] [--tui] [--no-tui] [-h|--help]
[NAMES]

💖 DESCRIPTION 💖

Build and save a fleet deployment plan for review. literally the whole point. you get a plan, it gets saved, you get to review it before the chaos. main character energy only. 👑

🌈 OPTIONS 🌈

  • --json — export the plan as JSON instead of showing you a summary plus the saved plan ID. machine-readable slay. 🤖
  • --user-config <USER_CONFIG> — use this user configuration file instead of the XDG default. not me overriding the default, i would never (i would). 🙈
  • [NAMES] — machine names. defaults to every machine with target.host. if you don't say who, it says everyone. 💀

🔥 INPUT OVERRIDES 🔥

  • --from <FROM> — the source for devenv.nix.

can be either a filesystem path (with the path: prefix) or a flake input reference.

examples, bestie, take notes:

--from github:cachix/devenv
--from github:cachix/devenv?dir=examples/simple
--from path:/absolute/path/to/project
--from path:./relative/path
  • -o, --override-input <NAME> <URI> — override inputs in devenv.yaml. so iconic of you.

examples:

--override-input nixpkgs github:NixOS/nixpkgs/nixos-unstable
--override-input nixpkgs path:/path/to/local/nixpkgs
  • -O, --option <OPTION:TYPE> <VALUE> — override configuration options with typed values. fancy fr fr.

OPTION must include a type: <attribute>:<type>. supported types: string, int, float, bool, path, pkg, pkgs.

list types (pkgs) append to existing values by default. add a ! suffix to replace instead: pkgs!. the ! is giving "no, actually, replace it" energy.

examples:

--option languages.rust.channel:string beta
--option services.postgres.enable:bool true
--option languages.python.version:string 3.10
--option packages:pkgs "ncdu git"       (appends to packages)
--option packages:pkgs! "ncdu git"      (replaces all packages)

🦋 NIX OPTIONS 🦋

  • -j, --max-jobs <MAX_JOBS> — max number of Nix builds running at the same time. defaults to 1/4 of available CPU cores (minimum 1). multitasking but make it responsible. ✨
  • -u, --cores <CORES> — number of CPU cores each build gets. defaults to available cores divided by max-jobs (minimum 1). sharing is caring. 💜
  • -s, --system <SYSTEM> — override the target system. defaults to the host system (e.g. aarch64-darwin, x86_64-linux). 🖥️
  • -i, --impure — relax the hermeticity of the environment. letting the outside world in, lowkey. 🫧
  • --no-impure — force a hermetic environment, overriding config. no outside world. none. 🙅‍♀️
  • --offline — disable substituters and consider all previously downloaded files up-to-date. airplane mode but for Nix. ✈️
  • --nix-option <NAME> <VALUE> — pass additional options to nix commands. these go straight to Nix using the --option flag. see man nix.conf for the full list of available options.

examples:

--nix-option sandbox false
--nix-option keep-outputs true
--nix-option system x86_64-darwin
  • --nix-debugger — enter the Nix debugger on failure. when it goes wrong, go deep. 🕵️‍♀️

🐚 SHELL OPTIONS 🐚

  • -c, --clean [<CLEAN>...] — ignore existing environment variables when entering the shell. pass a list of comma-separated environment variables to let through. a little velvet rope for your env vars. 🎀
  • -P, --profile <PROFILES> — activate one or more profiles defined in devenv.nix.

profiles let you define different configurations that get merged with your base configuration.

see https://devenv.sh/profiles for more information.

examples:

--profile python-3.14
--profile backend --profile fast-startup
  • --reload — enable auto-reload when config files change (default). she's always watching. 👀
  • --no-reload — disable auto-reload when config files change. she's off duty.
  • --shell <SHELL_TYPE> — which shell to use for interactive sessions (bash, zsh, fish, nu).

possible values:

  • bash
  • zsh
  • fish
  • nu

🍓 CACHE OPTIONS 🍓

  • --eval-cache — enable caching of Nix evaluation results (default). memory of a queen. 🧠
  • --no-eval-cache — disable caching of Nix evaluation results. starting fresh, no baggage.
  • --refresh-eval-cache — force a refresh of the Nix evaluation cache. clean slate era. 🧼
  • --refresh-task-cache — force a refresh of the task cache. same energy, different cache. 🫶

🧚 SECRETSPEC OPTIONS 🧚

  • --secretspec-provider <SECRETSPEC_PROVIDER> — override the secretspec provider. 🤫
  • --secretspec-profile <SECRETSPEC_PROFILE> — override the secretspec profile. 🤫✨

⭐ TRACING OPTIONS ⭐

  • --trace-to <TRACE_TO> — enable tracing and set output destination(s). can be repeated for multiple outputs. yes bestie you can have several. 💅

syntax: [format:]destination

examples:

--trace-to stderr                              # json to stderr
--trace-to pretty:stderr                       # pretty format to stderr
--trace-to json:file:/tmp/trace.json           # JSON to file
--trace-to otlp-grpc                           # OTLP gRPC to default endpoint
--trace-to otlp-grpc:http://collector:4317     # OTLP gRPC to custom endpoint

multiple outputs:

--trace-to pretty:stderr --trace-to json:file:/tmp/t.json

destinations: stdout, stderr, file:<path>, http(s)://<host>:<port>. formats: json (default), pretty, full, otlp-grpc, otlp-http-protobuf, otlp-http-json.

when the format is omitted, it defaults to json. tracing is disabled by default. 🔕

[env: DEVENV_TRACE_TO=] (comma-separated) — [env: DEVENV_TRACE_DEFAULT_TO=] (comma-separated, used only when no explicit tracing is configured; set to empty string to suppress).

ok that env-var bit is dense even for me — read it twice, it's worth it. 🫡

👑 GLOBAL OPTIONS 👑

  • -v, --verbose — enable additional debug logs. she's telling you everything. 🗣️
  • -q, --quiet — silence all logs. not a word. 🤐
  • --tui <TUI> — enable the interactive terminal interface (default when interactive).

possible values:

  • true
  • false
  • --no-tui — disable the interactive terminal interface. plain text era.
  • -h, --help — print help (see a summary with '-h'). bestie, read the docs. 📖
word of warning from your girl: --offline turns off substituters and treats everything already downloaded as up-to-date, --no-impure overrides your config to force hermeticity, and --option ...:pkgs! replaces all packages rather than appending. read before you wreck. 😭

and that's the page!! this absolute icon is plan from devenv-machines-plan(1) — go build that plan, review it, and slay responsibly. periodt. 💖✨🎀🦋🌸💅🫶🌈⭐👑

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