flox activate

NAME

flox-activate - activate environments

SYNOPSIS

flox [<general-options>] activate
     [-d=<path> | -r=<owner>/<name>]
     [-t]
     [--print-script]
     [--start-services | --no-start-services]
     [-m=(dev|run)]
     [-g=<generation>]
     [-c=<shell command> | -- <exec command>...]

DESCRIPTION

Configures a shell with everything defined by the environment:

Downloads packages and adds their bin directories to your $PATH.
Sets environment variables and aliases.
Runs hooks.
Starts services (if --start-services is specified).

flox activate may run in one of four modes:

interactive: flox activate when invoked from an interactive shell
Launches an interactive sub-shell. The shell to be launched is determined by $FLOX_SHELL or $SHELL.
shell command: flox activate -c CMD
Runs CMD in the same environment as if run inside an interactive shell produced by an interactive flox activate. The shell CMD is run by is determined by $FLOX_SHELL or $SHELL. Because CMD is passed to a shell, shell features like running multiple commands with && can be used.
exec command: flox activate -- CMD
Execs CMD directly after performing all parts of activation except for running scripts in [profile].
in-place: flox activate when invoked from a non-interactive shell with its stdout redirected e.g. eval "$(flox activate)"
Produces commands to be sourced by the parent shell. Flox will determine the parent shell from $FLOX_SHELL or otherwise automatically determine the parent shell and fall back to $SHELL.

flox activate currently supports bash, fish, tcsh, and zsh shells for any of the detection mechanisms described above.

When invoked interactively, the shell prompt will be modified to display the active environments, as shown below:

flox [env1 env2 env3] <normal prompt>

When multiple environments are activated each of their shell hooks (profile and hook scripts) are executed in the context of the environment that they come from. This means that for each shell hook various environment variables such as PATH, MANPATH, PKG_CONFIG_PATH, PYTHONPATH, etc, are set to the appropriate values for the environment in which the shell hook was defined. See manifest.toml(5) for more details on shell hooks.

To reverse activation, run flox-deactivate(1). Inside a flox activate subshell, flox deactivate is equivalent to exit.

OPTIONS

Activate Options

-c <command>, --command <command> Shell command string to run in a subshell started in the activated environment

-- <command> [<arguments>] Command to exec in the activated environment. This does not run any profile scripts

-t, --trust Trust a remote environment for this activation. Activating an environment executes a shell hook which may execute arbitrary code. This presents a security risk, so you will be prompted whether to trust the environment. Environments owned by the current user and Flox are always trusted. You may set certain environments to always be trusted using the config key trusted_environments."<owner/name>" = (trust | deny), or via the following command: flox config --set trusted_environments.\"<owner/name>\" trust.

--print-script Prints an activation script to stdout that's suitable for sourcing in a shell rather than activation via creating a subshell. flox automatically knows when to print the activation script to stdout, so this command is just a debugging aid for users.

-s, --start-services Start the services listed in the manifest when activating the environment. If no services are running, the services from the manifest will be started, otherwise a warning will be displayed and activation will continue.

To start services by default without requiring -s, set services.auto-start = true in the manifest.

The services started with this flag will be cleaned up once the last activation of this environment terminates.

A remote environment can only have a single set of running services, regardless of how many times the environment is activated concurrently.

--no-start-services Don't start services even if configured in the manifest with auto-start = true.

-m (dev|run), --mode (dev|run) Activate the environment in either "dev" or "run" mode. Overrides the options.activate.mode setting in the manifest. See manifest.toml(5) for more details on activation modes.

-g <generation>, --generation <generation> Activate a FloxHub environment at a specific generation.

Environment Options

If no environment is specified for an environment command, the environment in the current directory or the active environment that was last activated is used.

-d, --dir Path containing a .flox/ directory.

-r, --reference A FloxHub environment, specified in the form <owner>/<name>.

-D, --default Use your default environment (<your-user>/default). When unauthenticated in an interactive context, you will be prompted to log in. In non-interactive contexts (e.g., scripts or CI), this flag will fail with an error when authentication is missing.

General Options

-h, --help Prints help information.

The following options can be passed when running any flox subcommand but must be specified before the subcommand.

-v, --verbose Increase logging verbosity. Invoke multiple times for increasing detail.

-q, --quiet Silence logs except for errors.

ENVIRONMENT VARIABLES

Variables set by flox activate

$FLOX_ENV Contains the path to the built environment. This directory contains a merged set of bin, lib, etc directories for all the packages in the environment.

$FLOX_PROMPT_ENVIRONMENTS Contains a space-delimited list of the active environments, e.g. owner1/foo owner2/bar local_env. If hide_default_prompt is set to true, environments named default are excluded.

$FLOX_ENV_CACHE activate sets this variable to a directory that can be used by an environment's hook to store transient files. These files will persist for environments used locally, but they will not be pushed, and they will not persist when using a remote environment with -r.

$FLOX_ENV_PROJECT activate sets this variable to the directory of the project using the Flox environment. For environments stored locally, this is the directory containing the environment. When running flox activate -r, this is set to the current working directory. This variable can be used to find project files in environment hooks.

$FLOX_ENV_DESCRIPTION activate sets this variable to the project name of the environment. It can be used to identify or construct messages about the environment.

$_FLOX_ACTIVE_ENVIRONMENTS A JSON array containing one object per active environment. This is currently an implementation detail and its contents are subject to change.

$FLOX_ACTIVATE_START_SERVICES "true" if this activation started services, "false" otherwise.

Variables used by flox activate

$FLOX_SHELL, $SHELL When activating an environment Flox will either launch a sub-shell or emit commands to configure an already-running (parent) shell. In both of these cases Flox needs to know which shell to use, and these variables are used to control the selection process.

interactive and command modes: When launching a sub-shell Flox will invoke the shell specified in $FLOX_SHELL if set or fall back to invoke $SHELL by default.
in-place mode: When performing an "in place" activation Flox will attempt to detect its parent shell type unless overridden by the $FLOX_SHELL variable, and if it cannot detect its parent shell type then will produce a script with syntax determined by $SHELL.

$FLOX_PROMPT_COLOR_{1,2} Flox adds text to the beginning of the shell prompt to indicate which environments are active. A set of default colors are used to color this prompt, but the colors may be overridden with the $FLOX_PROMPT_COLOR_1 and $FLOX_PROMPT_COLOR_2 environment variables.

The values of these variables should be integers chosen from the 256-color palette as described in the xterm-256color chart.

EXAMPLES

Activate an environment stored in the current directory:

flox activate

Activate an environment some_user/myenv that's been pushed to FloxHub:

flox activate -r some_user/myenv

Invoke a command inside an environment without entering its subshell:

flox activate -- cmd --some-arg arg1 arg2

Activate default Flox environment only within the current shell (add to the relevant "rc" file, e.g. ~/.bashrc or ~/.zprofile):

eval "$(flox activate)"