From 19c5f1834e15ad5ee9ee4d6e0ae35a4e6c05e46d Mon Sep 17 00:00:00 2001
From: jdx <216188+jdx@users.noreply.github.com>
Date: Mon, 2 Mar 2026 01:02:57 +0000
Subject: [PATCH 1/2] fix(task): remove deprecated `# mise` task header syntax

The old `# mise ...` syntax was deprecated in favor of `#MISE ...` and
scheduled for removal in 2026.3.0. Remove the old syntax handling and
the debug_assert reminder that was causing panics in debug builds.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
---
 src/task/mod.rs | 21 +--------------------
 1 file changed, 1 insertion(+), 20 deletions(-)

diff --git a/src/task/mod.rs b/src/task/mod.rs
index 85337c8585..cc45b00f4c 100644
--- a/src/task/mod.rs
+++ b/src/task/mod.rs
@@ -1,4 +1,3 @@
-use crate::cli::version::VERSION;
 use crate::config::config_file::mise_toml::EnvList;
 use crate::config::config_file::toml::{TrackingTomlParser, deserialize_arr};
 use crate::config::env_directive::{EnvDirective, EnvResolveOptions, EnvResults, ToolsFilter};
@@ -306,25 +305,7 @@ impl Task {
         let info = file::read_to_string(path)?
             .lines()
             .filter_map(|line| {
-                debug_assert!(
-                    !VERSION.starts_with("2026.3"),
-                    "remove old syntax `# mise`"
-                );
-                if let Some(captures) =
-                    regex!(r"^(?:#|//|::)(?:MISE| ?\[MISE\]) ([a-z0-9_.-]+=[^\n]+)$").captures(line)
-                {
-                    Some(captures)
-                } else if let Some(captures) = regex!(r"^(?:#|//) mise ([a-z0-9_.-]+=[^\n]+)$")
-                    .captures(line)
-                {
-                    deprecated!(
-                        "file_task_headers_old_syntax",
-                        "The `# mise ...` syntax for task headers is deprecated and will be removed in mise 2026.3.0. Use the new `#MISE ...` syntax instead."
-                    );
-                    Some(captures)
-                } else {
-                    None
-                }
+                regex!(r"^(?:#|//|::)(?:MISE| ?\[MISE\]) ([a-z0-9_.-]+=[^\n]+)$").captures(line)
             })
             .map(|captures| captures.extract().1)
             .map(|[toml]| {

From 781a543f8fd83a051729081c266f3b2d20c79796 Mon Sep 17 00:00:00 2001
From: jdx <216188+jdx@users.noreply.github.com>
Date: Mon, 2 Mar 2026 01:11:44 +0000
Subject: [PATCH 2/2] fix(task): update test to use new #MISE header syntax

The test_from_path_invalid_toml test was still using the old deprecated
`# mise` syntax which is no longer parsed after the previous commit.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
---
 src/task/mod.rs | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/task/mod.rs b/src/task/mod.rs
index cc45b00f4c..d05197edfb 100644
--- a/src/task/mod.rs
+++ b/src/task/mod.rs
@@ -1621,8 +1621,8 @@ echo "hello world"
         fs::write(
             &task_path,
             r#"#!/bin/bash
-# mise description="test task"
-# mise env={invalid=toml=here}
+#MISE description="test task"
+#MISE env={invalid=toml=here}
 echo "hello world"
 "#,
         )