Release/v0.5.1

CHANGELOG.md

@@ -6,6 +6,12 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/),
 and this project is in 0.x, minor versions may add, change, or remove
 functionality freely; 1.0.0 marks a stable command surface.
 
+## [0.5.1] — 2026-08-30
+
+### Fixed
+- Running `commitor scan` outside a git repository now stops with a clear
+  "not a git repository" message instead of git's raw diff usage dump.
+
 ## [0.5.0] — 2026-08-29
 
 ### Added
@@ -188,6 +194,7 @@ not of the full tool.
 - `commitor scan` and `commitor commit` — in active development,
   coming in future 0.x releases.
 
+[0.5.1]: https://github.com/Commitor-AI/commitor/releases/tag/v0.5.1
 [0.5.0]: https://github.com/Commitor-AI/commitor/releases/tag/v0.5.0
 [0.4.0]: https://github.com/Commitor-AI/commitor/releases/tag/v0.4.0
 [0.3.3]: https://github.com/Commitor-AI/commitor/releases/tag/v0.3.3

crates/cli/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "commitor-cli"
-version = "0.5.0"
+version = "0.5.1"
 edition = "2021"
 description = "Catches unrelated changes bundled into commits and splits them cleanly — whole-file or hunk-level, guided by AI analysis"
 license = "MIT OR Apache-2.0"

crates/cli/src/engine/git.rs

@@ -33,6 +33,17 @@ pub fn get_branch_diff(base: &str) -> Result<String> {
     run_git(&["diff", &format!("{base}...HEAD")])
 }
 
+/// True when the current directory is inside a git work tree (bare
+/// repos and `.git` directories report `false`). Checks `rev-parse
+/// --is-inside-work-tree` because `git diff` outside a repo falls into
+/// `--no-index` mode and prints an unrelated usage dump instead of the
+/// usual "not a git repository" error.
+pub fn is_work_tree() -> bool {
+    run_git(&["rev-parse", "--is-inside-work-tree"])
+        .map(|out| out.trim() == "true")
+        .unwrap_or(false)
+}
+
 /// The full patch text of one diff flavor: staged when `staged`,
 /// unstaged (working tree) otherwise.
 pub fn diff_patch(staged: bool) -> Result<String> {

crates/cli/src/scan.rs

@@ -17,6 +17,7 @@ use std::process::ExitCode;
 use anyhow::{bail, Result};
 
 use crate::analysis;
+use crate::engine::git;
 use crate::heuristics::{self, Verdict};
 
 #[derive(Debug, Default)]
@@ -46,6 +47,10 @@ fn scan_escalates(verdict: &Verdict, diff_range: bool) -> bool {
 }
 
 pub fn run(flags: ScanFlags) -> Result<ExitCode> {
+    if !git::is_work_tree() {
+        bail!("this doesn't look like a git repository — run `commitor scan` from inside a git repository");
+    }
+
     // Machine-readable output modes suppress the human progress lines.
     let quiet = flags.json || flags.markdown;
 

npm/package.json

@@ -1,6 +1,6 @@
 {
   "name": "commitor-cli",
-  "version": "0.5.0",
+  "version": "0.5.1",
   "description": "Catches unrelated changes bundled into commits and splits them cleanly — whole-file or hunk-level, guided by AI analysis",
   "bin": {
     "commitor": "bin/commitor.js"