devenv-init(1)

📦
version 2.4.0 · 2 versions
, in nixpkgs unstable

💅 devenv-init(1) 🎀

okay so bestie, buckle up — this is devenv-init from the General Commands Manual, and honestly? it's giving "starter pack but make it cute." let's go ✨

🌸 NAME 🌸

devenv-init — scaffold devenv.yaml, devenv.nix, and .gitignore. that's the whole vibe, no cap 💖

🦋 SYNOPSIS 🦋

devenv init [--include-envrc] [--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]
[TARGET]

like, yes, it's a lot of brackets — think of them as lil accessories, every one of them optional 💅

🌈 DESCRIPTION 🌈

scaffold devenv.yaml, devenv.nix, and .gitignore. boom. that's literally the whole personality. your project gets its little starter set and it is iconic 🫶

✨ OPTIONS ✨

🎀 the basics

  • --include-envrc — also drop in a .envrc file. yes bestie, direnv girlies rise 💖
  • --user-config <USER_CONFIG> — point at this user config file instead of the XDG default. main character config energy 👑
  • [TARGET] — the optional target. it's just... there. sitting pretty 🦋

🌀 INPUT OVERRIDES 🌀

  • --from <FROM> — where your devenv.nix comes from.

can be either a filesystem path (with a path: prefix) or a flake input reference. so many options, so little time 😭

examples, bestie:

--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 inside devenv.yaml. lowkey one of the most useful things here fr fr

examples:

--override-input nixpkgs github:NixOS/nixpkgs/nixos-unstable
--override-input nixpkgs path:/path/to/local/nixpkgs
  • -O, --option <OPTION:TYPE> <VALUE> — override config options with typed values. type safety but make it fashion ✨

OPTION must include a type in the form <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! 💀 (yes that exclamation mark is doing a lot of heavy lifting)

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> — how many Nix builds run at the same time. maximum multitasking energy 🧚

defaults to 1/4 of available CPU cores (minimum 1).

  • -u, --cores <CORES> — how many CPU cores each build gets. sharing is caring 💜

defaults to available cores divided by max-jobs (minimum 1).

  • -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, respectfully 🙈
  • --no-impure — force a hermetic environment, overriding config. no vibes from outside allowed, periodt 🚫
  • --offline — disable substituters and consider all previously downloaded files up-to-date. airplane mode but for Nix ✈️
  • --nix-option <NAME> <VALUE> — pass extra options to nix commands.

these get passed straight to Nix using the --option flag. see man nix.conf for the full list of available options — it's a lot, iykyk.

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 things go wrong, go full detective mode 🔍😭

🐚 SHELL OPTIONS 🐚

  • -c, --clean [<CLEAN>...] — ignore existing environment variables when entering the shell. pass a list of comma-separated environment variables to let through. clean slate, fresh start, new me 🌸
  • -P, --profile <PROFILES> — activate one or more profiles defined in devenv.nix.

profiles let you define different configurations that can be merged with your base configuration. it's giving "outfit changes" 💅

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. sometimes you just need peace and quiet 🤫
  • --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). speed, slay, repeat ⚡
  • --no-eval-cache — disable caching of Nix evaluation results. living dangerously, honestly 💀
  • --refresh-eval-cache — force a refresh of the Nix evaluation cache. out with the old ✨
  • --refresh-task-cache — force a refresh of the task cache. same energy, different cache 🧹

🔐 SECRETSPEC OPTIONS 🔐

  • --secretspec-provider <SECRETSPEC_PROVIDER> — override the secretspec provider. secrets but make it specified 🤫
  • --secretspec-profile <SECRETSPEC_PROFILE> — override the secretspec profile. profile inception, we love to see it 💜

⭐ TRACING OPTIONS ⭐

  • --trace-to <TRACE_TO> — enable tracing and set output destination(s). can be repeated for multiple outputs. more destinations = more data = more fun, obviously 🔥

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 format is omitted, defaults to json. tracing is disabled by default.

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

👑 GLOBAL OPTIONS 👑

  • -v, --verbose — enable additional debug logs. she's chatty and we respect it 💬
  • -q, --quiet — silence all logs. shhh. not a peep 🤫
  • --tui <TUI> — enable the interactive terminal interface (default when interactive).

possible values:

  • true
  • false
  • --no-tui — disable the interactive terminal interface. some days you just want plain text, and that's valid 🫶
  • -h, --help — print help (see a summary with -h). cute lil shortcut for the impatient girlies ⭐
ok real talk bestie: --offline, --impure/--no-impure, and all those override flags genuinely change how your environment behaves. read before you yeet 🫶

and that's the whole page, no crumbs left 💖 this was devenv-init(1) from the General Commands Manual, version init, closing out the devenv-init(1) footer like a proper sign-off — bye bestie, go scaffold something iconic 🎀🦋✨

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