Environment plugins run far too eagerly

[DexterHill0]

Something that I have seemed to notice (on both windows and linux) is that environment plugins seem to run very eagerly. Perhaps this is a configuration issue of my particular plugin, but it runs for every command I invoke, not just mise commands (while writing I realised I guess this makes sense, but sometimes that means it runs out of order which can be annoying), it runs 4 times before any mise task is executed (I have an info log inside the plugin that prints 4 times before the tasks starts), and it also seems to execute after any mise command has been executed as well (for example, mise env will run the plugin once, then print the environment variables, then run it again).

Again, this may be a configuration issue on my part, but I'd love to know how I can stop environment plugins from running so many times.

mise doctor

version: 2026.3.9 windows-x64 (2026-03-13) shims_on_path: yes self_update_available: yes

build_info:
Target: x86_64-pc-windows-msvc
Features: DEFAULT, NATIVE_TLS, OPENSSL, RUSTLS_NATIVE_ROOTS, SELF_UPDATE
Built: Fri, 13 Mar 2026 19:08:15 +0000
Rust Version: rustc 1.93.1 (01f6ddf75 2026-02-11)
Profile: release

shell:
pwsh
PowerShell 7.5.4

aqua:
baked in registry tools: 2259

dirs:
cache: D:\Dexter\AppData\Local\Temp\mise
config: ~.config\mise
data: ~\AppData\Local\mise
shims: ~\AppData\Local\mise\shims
state: ~.local\state\mise

config_files:
~.config\mise\config.toml

ignored_config_files: (none)

backends:
aqua
asdf
cargo
conda
core
dotnet
forgejo
gem
github
gitlab
go
npm
pipx
spm
http
s3
ubi
vfox

plugins:

toolset:
core:node@25.8.1
core:python@3.14.3

path:
C:\Program Files\PowerShell\7
D:\Program Files\Zulu\zulu-21\bin
D:\Program Files (x86)\VMware\VMware Player\bin
C:\WINDOWS\system32
C:\WINDOWS
C:\WINDOWS\System32\Wbem
C:\WINDOWS\System32\WindowsPowerShell\v1.0
C:\WINDOWS\System32\OpenSSH
C:\Program Files (x86)\NVIDIA Corporation\PhysX\Common
D:\Program Files\npm
D:\Program Files\spwn
D:\Program Files\BinDiff\bin
C:\Program Files\usbipd-win
C:\Program Files\dotnet
D:\Programs\Scoop\Apps\apps\gpg4win\current\Gpg4win..\GnuPG\bin
C:\Program Files (x86)\Windows Kits\10\Windows Performance Toolkit
C:\Program Files\NVIDIA Corporation\NVIDIA App\NvDLISR
C:\Program Files\PowerShell\7
D:\Programs\Scoop\Apps\shims
D:\Dexter.cargo\bin
~\scoop\shims
~\AppData\Local\mise\installs\infisical\0.43.58
C:\Program Files\PowerShell\7
D:\Program Files\Zulu\zulu-21\bin
D:\Program Files (x86)\VMware\VMware Player\bin
C:\WINDOWS\system32
C:\WINDOWS
C:\WINDOWS\System32\Wbem
C:\WINDOWS\System32\WindowsPowerShell\v1.0
C:\WINDOWS\System32\OpenSSH
C:\Program Files (x86)\NVIDIA Corporation\PhysX\Common
D:\Program Files\npm
D:\Program Files\spwn
D:\Program Files\BinDiff\bin
C:\Program Files\usbipd-win
C:\Program Files\dotnet
D:\Programs\Scoop\Apps\apps\gpg4win\current\Gpg4win..\GnuPG\bin
C:\Program Files (x86)\Windows Kits\10\Windows Performance Toolkit
C:\Program Files\NVIDIA Corporation\NVIDIA App\NvDLISR
C:\Program Files\PowerShell\7
D:\Programs\Scoop\Apps\apps\llvm\current\bin
D:\Programs\Scoop\Apps\apps\gpg4win\current\GnuPG\bin
D:\Programs\Scoop\Apps\apps\gpg4win\current\Gpg4win\bin
D:\Programs\Scoop\Apps\apps\mpv\current
~\AppData\Local\pnpm
D:\Programs\Scoop\Apps\apps\nvm\current
D:\Programs\Scoop\Apps\apps\nvm\current\nodejs\n
~\AppData\Local\mise\installs\node\25.8.1
~\AppData\Local\mise\installs\python\3.14.3
~\AppData\Local\mise\shims
C:\WINDOWS\System32\WindowsApps
~\AppData\Local\Microsoft\WindowsApps
D:\Dexter\AppData\Local\Programs\Microsoft VS Code\bin
D:\Programs\Scoop\Apps\apps\git\current\bin
~\AppData\Local\Microsoft\WinGet\Links

env_vars:
MISE_SHELL=pwsh

settings:
experimental false ~.config\mise\config.toml

No problems found

[jdx]

This is expected behavior but there are ways to improve it. Here's what's happening:

Why it runs so often

Every shell prompt: mise activate installs a hook that runs mise hook-env on every prompt. This re-evaluates your environment (including env modules) to detect changes. This is why it seems to run for "every command" — it's actually running on every prompt, not every command.

Multiple times before a task: The env module gets evaluated in two phases:

1. Non-tools phase — resolves env modules that don't depend on tool paths (tools = false, the default)
2. Tools phase — resolves env modules with tools = true after tool paths are set up

Plus mise hook-env fires on the prompt before mise run, and then mise run itself evaluates the environment. That could account for the multiple invocations you're seeing.

After mise env: The prompt hook fires after mise env completes, re-evaluating the module.

How to reduce executions

1. Enable env caching (recommended)

Add to your ~/.config/mise/config.toml:

[settings]
env_cache = true
# env_cache_ttl = "1h"  # default, adjust as needed

Then in your plugin's MiseEnv hook, return the extended format:

function PLUGIN:MiseEnv(ctx)
  return {
    cacheable = true,
    watch_files = {"path/to/config/that/would/change/results"},
    env = {
      { key = "MY_VAR", value = "my_value" }
    }
  }
end

With caching enabled, the plugin only re-runs when watched files change or the TTL expires.

2. Use hook_env.cache_ttl

This throttles how often hook-env does a full re-evaluation:

[settings]
hook_env.cache_ttl = "5s"  # skip re-evaluation if checked within 5 seconds

3. Use hook_env.chpwd_only

If you only need the env to update on directory changes (not every prompt):

[settings]
hook_env.chpwd_only = true

---

The combination of env_cache = true + cacheable = true in your plugin should dramatically reduce the number of times your plugin actually executes.

This comment was generated by Claude Code.