Switch to clap's dynamic completion engine

Cargo.toml

@@ -23,6 +23,7 @@ blake3 = { version = "1.5.0", features = ["rayon", "mmap"] }
 camino = "1.0.4"
 chrono = "0.4.38"
 clap = { version = "4.0.0", features = ["derive", "env", "wrap_help"] }
+clap_complete = { version = "4.6.0", features = ["unstable-dynamic"] }
 clap_mangen = "0.2.20"
 derive-where = "1.2.7"
 dirs = "6.0.0"
@@ -58,7 +59,6 @@ nix = { version = "0.31.0", features = ["signal", "user", "fs"] }
 ctrlc = { version = "3.1.1", features = ["termination"] }
 
 [dev-dependencies]
-clap_complete = "=4.5.48"
 pretty_assertions = "1.0.0"
 temptree = "0.2.0"
 which = "8.0.0"

README.md

@@ -4454,47 +4454,66 @@ described in the next section. Add the following line to your `.bashrc` to use
 the same completion function as `just` for your aliased command:
 
 ```console
-complete -F _just -o bashdefault -o default j
+complete -F _clap_complete_just -o bashdefault -o default j
 ```
 
 ### Shell Completion Scripts
 
-Shell completion scripts for Bash, Elvish, Fish, Nushell, PowerShell, and Zsh
-are available [release archives](https://github.com/casey/just/releases).
+Completion scripts are generated by the `just` binary itself and should be
+generated and sourced on shell startup.
 
-The `just` binary can also generate the same completion scripts at runtime
-using `just --completions SHELL`:
+#### Bash
 
-```console
-$ just --completions zsh > just.zsh
+In `~/.bashrc`:
+
+```bash
+source <(just --completions bash)
 ```
 
-Please refer to your shell's documentation for how to install them.
+#### The Z Shell
 
-*macOS Note:* Recent versions of macOS use zsh as the default shell. If you use
-Homebrew to install `just`, it will automatically install the most recent copy
-of the zsh completion script in the Homebrew zsh directory, which the built-in
-version of zsh doesn't know about by default. It's best to use this copy of the
-script if possible, since it will be updated whenever you update `just` via
-Homebrew. Also, many other Homebrew packages use the same location for
-completion scripts, and the built-in zsh doesn't know about those either. To
-take advantage of `just` completion in zsh in this scenario, you can set
-`fpath` to the Homebrew location before calling `compinit`. Note also that Oh
-My Zsh runs `compinit` by default. So your `.zshrc` file could look like this:
+In `~/.zshrc`:
 
 ```zsh
-# Init Homebrew, which adds environment variables
-eval "$(brew shellenv)"
+source <(just --completions zsh)
+```
+
+#### Fish
+
+In `~/.config/fish/config.fish`:
+
+```fish
+just --completions fish | source
+```
+
+#### Elvish
+
+In `~/.elvish/rc.elv`:
 
-fpath=($HOMEBREW_PREFIX/share/zsh/site-functions $fpath)
+```elvish
+eval (just --completions elvish | slurp)
+```
+
+#### PowerShell
+
+In `$PROFILE`:
+
+```powershell
+just --completions powershell | Out-String | Invoke-Expression
+```
+
+#### Nushell
+
+Write the completion script to disk:
+
+```nu
+just --completions nushell | save -f ~/.config/nushell/just.nu
+```
 
-# Then choose one of these options:
-# 1. If you're using Oh My Zsh, you can initialize it here
-# source $ZSH/oh-my-zsh.sh
+In `config.nu`:
 
-# 2. Otherwise, run compinit yourself
-# autoload -U compinit
-# compinit
+```nu
+use just.nu *
 ```
 
 ### Man Page

bin/package

@@ -34,7 +34,6 @@ cp -r \
   GRAMMAR.md \
   LICENSE \
   README.md \
-  completions \
   man/just.1 \
   $DIST