refactor(prepare): remove touch_outputs and update docs to reflect blake3 hashing

docs/dev-tools/prepare.md

@@ -1,8 +1,7 @@
 # Prepare <Badge type="warning" text="experimental" />
 
-The `mise prepare` command ensures project dependencies are ready by checking if lockfiles
-are newer than installed outputs (e.g., `package-lock.json` vs `node_modules/`) and running
-install commands if needed.
+The `mise prepare` command ensures project dependencies are ready by hashing source files
+(e.g., `package-lock.json`) and running install commands when changes are detected.
 
 ## Quick Start
 
@@ -87,37 +86,33 @@ run = "npx prisma generate"
 
 ### Provider Options
 
-| Option          | Type     | Description                                                                     |
-| --------------- | -------- | ------------------------------------------------------------------------------- |
-| `auto`          | bool     | Auto-run before `mise x` and `mise run` (default: false)                        |
-| `sources`       | string[] | Files/patterns to check for changes                                             |
-| `outputs`       | string[] | Files/directories that should be newer than sources                             |
-| `run`           | string   | Command to run when stale                                                       |
-| `env`           | table    | Environment variables to set                                                    |
-| `dir`           | string   | Working directory for the command                                               |
-| `description`   | string   | Description shown in output                                                     |
-| `touch_outputs` | bool     | Touch output mtimes after a successful run so they appear fresh (default: true) |
-| `depends`       | string[] | Other provider names that must complete before this one runs                    |
-| `timeout`       | string   | Timeout for the run command, e.g., `"30s"`, `"5m"` (default: no timeout)        |
+| Option        | Type     | Description                                                               |
+| ------------- | -------- | ------------------------------------------------------------------------- |
+| `auto`        | bool     | Auto-run before `mise x` and `mise run` (default: false)                  |
+| `sources`     | string[] | Files/patterns to check for changes                                       |
+| `outputs`     | string[] | Files/directories that must exist for the provider to be considered fresh |
+| `run`         | string   | Command to run when stale                                                 |
+| `env`         | table    | Environment variables to set                                              |
+| `dir`         | string   | Working directory for the command                                         |
+| `description` | string   | Description shown in output                                               |
+| `depends`     | string[] | Other provider names that must complete before this one runs              |
+| `timeout`     | string   | Timeout for the run command, e.g., `"30s"`, `"5m"` (default: no timeout)  |
 
 ## Freshness Checking
 
-mise uses modification time (mtime) comparison to determine if outputs are stale:
+mise uses blake3 content hashing to determine if sources have changed since the last
+successful run. Hashes are stored in `.mise/prepare-state.toml`.
 
-1. Find the most recent mtime among all source files
-2. Find the most recent mtime among all output files
-3. If any source is newer than all outputs, the provider is stale
+1. Compute blake3 hashes of all source files
+2. Compare against stored hashes from the last successful run
+3. If any file was added, removed, or changed, the provider is stale
 
 This means:
 
 - If you modify `package-lock.json`, `node_modules/` will be considered stale
 - If `node_modules/` doesn't exist, the provider is always stale
 - If sources don't exist, the provider is considered fresh (nothing to do)
-
-After a successful run, mise touches the mtime of each output to now (controlled by
-`touch_outputs`, default `true`). This ensures that commands which are no-ops when
-dependencies are already satisfied (e.g. `uv sync` when the venv is up to date) still
-mark outputs as fresh, preventing repeated stale warnings on subsequent invocations.
+- On first run (no stored state), the provider is always considered stale
 
 ## Auto-Prepare
 

schema/mise.json

@@ -2247,11 +2247,6 @@
           },
           "description": "Other prepare providers that must complete before this one runs"
         },
-        "touch_outputs": {
-          "type": "boolean",
-          "default": true,
-          "description": "Whether to update mtime of output files/dirs after a successful run"
-        },
         "timeout": {
           "type": "string",
           "description": "Timeout for the run command (e.g., \"30s\", \"5m\", \"1h\")"

src/prepare/engine.rs

@@ -3,7 +3,6 @@ use std::path::{Path, PathBuf};
 use std::sync::Arc;
 
 use eyre::Result;
-use filetime::FileTime;
 use tokio::sync::Semaphore;
 use tokio::task::JoinSet;
 
@@ -69,7 +68,6 @@ struct PrepareJob {
     id: String,
     cmd: super::PrepareCommand,
     outputs: Vec<PathBuf>,
-    touch: bool,
     depends: Vec<String>,
     timeout: Option<std::time::Duration>,
 }
@@ -346,7 +344,6 @@ impl PrepareEngine {
             if !freshness.is_fresh() {
                 let cmd = provider.prepare_command()?;
                 let outputs = provider.outputs();
-                let touch = provider.touch_outputs();
                 let depends = provider.depends();
                 let timeout = provider.timeout();
                 let reason = freshness.reason().to_string();
@@ -358,7 +355,6 @@ impl PrepareEngine {
                         id,
                         cmd,
                         outputs,
-                        touch,
                         depends,
                         timeout,
                     });
@@ -433,9 +429,6 @@ impl PrepareEngine {
             let pr = mpr.add(&job.cmd.description);
             match Self::execute_prepare_static(&job.cmd, &toolset_env, job.timeout) {
                 Ok(()) => {
-                    if job.touch {
-                        Self::touch_outputs(&job.outputs);
-                    }
                     pr.finish_with_message(format!("{} done", job.cmd.description));
                     Ok((PrepareStepResult::Ran(job.id), job.outputs))
                 }
@@ -587,9 +580,6 @@ impl PrepareEngine {
 
                         match result {
                             Ok(Ok(())) => {
-                                if job.touch {
-                                    Self::touch_outputs(&job.outputs);
-                                }
                                 pr.finish_with_message(format!("{} done", job.cmd.description));
                                 let step = PrepareStepResult::Ran(id.clone());
                                 Ok((id, step, job.outputs))
@@ -776,16 +766,4 @@ impl PrepareEngine {
         runner.execute()?;
         Ok(())
     }
-
-    /// Update the mtime of output files/directories to now
-    fn touch_outputs(outputs: &[PathBuf]) {
-        let now = FileTime::now();
-        for path in outputs {
-            if path.exists()
-                && let Err(e) = filetime::set_file_mtime(path, now)
-            {
-                warn!("failed to touch {}: {e}", path.display());
-            }
-        }
-    }
 }

src/prepare/mod.rs

@@ -129,11 +129,6 @@ pub trait PrepareProvider: Debug + Send + Sync {
         self.base().is_auto()
     }
 
-    /// Whether to update mtime of output files/dirs after a successful run
-    fn touch_outputs(&self) -> bool {
-        self.base().touch_outputs()
-    }
-
     /// Other prepare providers that must complete before this one runs
     fn depends(&self) -> Vec<String> {
         self.base().config.depends.clone()

src/prepare/providers/mod.rs

@@ -29,7 +29,7 @@ use std::path::{Path, PathBuf};
 use crate::prepare::rule::PrepareProviderConfig;
 
 /// Shared base for all prepare providers, holding the id, project root, and config.
-/// Provides common implementations for `id`, `is_auto`, and `touch_outputs`.
+/// Provides common implementations for `id` and `is_auto`.
 #[derive(Debug)]
 pub struct ProviderBase {
     pub(crate) id: String,
@@ -50,10 +50,6 @@ impl ProviderBase {
         self.config.auto
     }
 
-    pub fn touch_outputs(&self) -> bool {
-        self.config.touch_outputs.unwrap_or(true)
-    }
-
     /// Returns the effective root directory for resolving sources/outputs.
     /// When `dir` is set in config, returns `project_root/dir`; otherwise `project_root`.
     pub fn config_root(&self) -> PathBuf {

src/prepare/rule.rs

@@ -42,10 +42,6 @@ pub struct PrepareProviderConfig {
     pub dir: Option<String>,
     /// Optional description
     pub description: Option<String>,
-    /// Whether to update mtime of output files/dirs after a successful run (default: true)
-    /// This is useful when the prepare command is a no-op (e.g., `uv sync` when all is well)
-    /// so that the outputs appear fresh for subsequent freshness checks.
-    pub touch_outputs: Option<bool>,
     /// Other prepare providers that must complete before this one runs
     #[serde(default)]
     pub depends: Vec<String>,