devenv-tasks-run(1)

💅 devenv-tasks-run — Run tasks

okay so this is the devenv-tasks-run(1) page, from the General Commands Manual bestie, and it does exactly one thing but does it thoroughly: it runs tasks ✨

---

🌸 NAME 🌸

devenv-tasks-run — Run tasks.

🎀 SYNOPSIS 🎀

devenv tasks run [-m|--mode] [--show-output] [--input] [--input-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] [TASKS]

like, the whole guest list is here. iconic.

🦋 DESCRIPTION 🦋

Run tasks.

(that's the whole description in the original, and honestly? she said it all. main character energy, minimal words 💅)

✨ OPTIONS ✨

• -m, --mode <MODE> — the execution mode for tasks (it affects dependency resolution). default: before. the possible values are giving choose your adventure:
  • single: run only the specified task, no dependencies, you're on your own bestie
  • after: run the specified task and the tasks that run after it (downstream tasks)
  • before: run all dependency tasks first, then the specified task (upstream tasks)
  • all: run the specified task together with its upstream and downstream tasks, the whole squad
• --show-output — show task output for all tasks (it's equivalent to --verbose for tasks). lowkey just "let me see everything" mode 🫶
• --input <KEY=VALUE> — set a task input value. repeatable! the value gets parsed as JSON if it's valid, otherwise it's treated as a string. flexible king.
• --input-json <JSON> — set task inputs from a JSON object string. one blob, all the inputs 💖
• --user-config <USER_CONFIG> — use this user configuration file instead of the XDG default. pick your own file, no default behavior for you ✨
• [TASKS] — the tasks. the actual tasks. yeah.

🌈 INPUT OVERRIDES 🌈

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

can be either a filesystem path (with a path: prefix) or a flake input reference. slay, both options.

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.

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. ngl this one's the ✨fancy✨ one.

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!

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)

see that !? that's the difference between "add to my collection" and "burn it all down and start fresh" 💀

🔥 NIX OPTIONS 🔥

• -j, --max-jobs <MAX_JOBS> — maximum number of Nix builds to run concurrently.

defaults to 1/4 of the available CPU cores (minimum 1). yes, minimum 1, she's not letting you set it to zero.

• -u, --cores <CORES> — number of CPU cores available to each build.

defaults to the 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. breaking out of the clean room, respectfully.
• --no-impure — force a hermetic environment, overriding config. back in the clean room, no cap.
• --offline — disable substituters and consider all previously downloaded files up-to-date. airplane mode realness ✈️
• --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.

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 sideways, you go in 🕵️‍♀️

🐚 SHELL OPTIONS 🐚

• -c, --clean [<CLEAN>...] — ignore existing environment variables when entering the shell. pass a list of comma-separated environment variables to let through. spring cleaning but you get to pick who survives 🧹
• -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.

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> — 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). work smarter etc.
• --no-eval-cache — disable caching of Nix evaluation results. doing it the hard way fr.
• --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. also out with the old, but for tasks.

🔐 SECRETSPEC OPTIONS 🔐

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

(secrets stay secret, bestie 🤫)

⭐ TRACING OPTIONS ⭐

• --trace-to <TRACE_TO> — enable tracing and set output destination(s). can be repeated for multiple outputs 🔁

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, 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)

okay so those two env vars matter: DEVENV_TRACE_TO is the comma-separated one, and DEVENV_TRACE_DEFAULT_TO is also comma-separated but only used when you haven't configured explicit tracing — set it to an empty string if you want to suppress it 🫡

👑 GLOBAL OPTIONS 👑

• -v, --verbose — enable additional debug logs. she's telling you everything.
• -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).

---

and that's the page, bestie 🎀 every flag, every default, every example, preserved like a limited-edition collector's item. the manual is from run (that's the source/version chilling in the footer, right next to devenv-tasks-run(1)) and the date slot is literally empty in there — not me leaving a blank in the group chat, that's just how the page ships 🙈💖

go run your tasks. periodt 🦋