devenv-build(1)

💅 devenv-build(1) — the one where you build literally anything in devenv.nix

ok so first things first bestie, this is a page from the General Commands Manual — it's devenv-build(1), the manual entry for the build command. Say hi 👋

✨ NAME ✨

devenv-build — build any attribute in devenv.nix. yes. any. of them. 🫶

🌸 SYNOPSIS 🌸

devenv build [--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] [ATTRIBUTES]

🎀 DESCRIPTION 🎀

Build any attribute in devenv.nix. that's it. that's the whole vibe. it's giving "just build the thing" and honestly? iconic. 💅

⭐ OPTIONS ⭐

• --user-config <USER_CONFIG> — use this user configuration file instead of the XDG default. be a rebel, pick your own path 🙈
• [ATTRIBUTES] — the attributes you're building, bestie

🦋 INPUT OVERRIDES 🦋

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

can be either a filesystem path (with a path: prefix) or a flake input reference. both are valid, no cap.

Examples:

--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 powerful honestly 🔥

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. type safety? we love her 💖

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

List types (pkgs) append to existing values by default. add a ! suffix to replace instead: pkgs! ⚠️ (yes, appending vs. replacing is a whole different situation, choose wisely)

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 to run concurrently. it defaults to 1/4 of available CPU cores (minimum 1). so it's like, polite about it 🧚
• -u, --cores <CORES> — number of CPU cores available to each build. defaults to available cores divided by max-jobs (minimum 1). math! ✨
• -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 a little chaos in, respectfully 🌈
• --no-impure — force a hermetic environment, overriding config. back in the bubble bestie 🫧
• --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 options are passed directly to Nix using the --option flag. see man nix.conf for the full list of available options. yes, the full list 👑

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 💀, go debug 💀🔍

🍓 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 lil VIP list for your env vars 🎟️
• -P, --profile <PROFILES> — activate one or more profiles defined in devenv.nix.

Profiles allow you to define different configurations that can be merged with your base configuration. very mix-and-match of them 💅

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 already on, bestie ✨
• --no-reload — disable auto-reload when config files change.
• --shell <SHELL_TYPE> — the 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 💨
• --no-eval-cache — disable caching of Nix evaluation results.
• --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. out with the old, part two 🔄

🔐 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 the output destination(s). can be repeated for multiple outputs. yes, you can have more than one 👀

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 an empty string to suppress) 🫶

👑 GLOBAL OPTIONS 👑

• -v, --verbose — enable additional debug logs. nosy in the best way 🔎
• -q, --quiet — silence all logs 🤐
• --tui <TUI> — enable the interactive terminal interface (default when interactive).

Possible values:

• true
• false

• --no-tui — disable the interactive terminal interface.
• -h, --help — print help (see a summary with -h) 🥺

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and that's the page, bestie 💖 this whole manual entry is build (that's the source, right there) for devenv-build(1) — no date on this one, so don't come for me about timestamps 🙈 go build something gorgeous. periodt. 🎀✨