fix(tool-stub): detect binary names from single-file downloads

CLAUDE.md

@@ -11,6 +11,9 @@ This file provides guidance to Claude Code (claude.ai/code) when working with co
 - `mise run test:e2e` - Run end-to-end tests only
 - `mise run snapshots` - Update test snapshots with `cargo insta`
 
+### Debugging
+- Use `MISE_DEBUG=1` or `MISE_TRACE=1` environment variables to enable debug output (not `RUST_LOG`)
+
 ### Code Quality and Testing
 - `mise run lint` - Run all linting tasks
 - `mise run lint-fix` - Run linting and automatically fix issues

e2e/cli/test_generate_tool_stub

@@ -0,0 +1,45 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+# Test that tool-stub generation works for git-branchless
+
+echo "Testing tool-stub generation for git-branchless..."
+
+# Generate a tool stub for git-branchless
+mise generate tool-stub git-branchless \
+	--platform-url 'https://github.com/arxanas/git-branchless/releases/download/v0.10.0/git-branchless-v0.10.0-x86_64-unknown-linux-musl.tar.gz'
+
+# Check that the file was created
+if [[ ! -f git-branchless ]]; then
+	echo "FAIL: Tool stub file was not created"
+	exit 1
+fi
+
+# Check that it's executable
+if [[ ! -x git-branchless ]]; then
+	echo "FAIL: Tool stub is not executable"
+	exit 1
+fi
+
+echo "Tool stub created successfully"
+
+# Show the stub content for debugging
+echo "Stub content:"
+cat git-branchless
+
+# Try to execute it to see the version
+# This will install the tool if we're on Linux x64, otherwise will show an error about platform
+echo "Attempting to execute git-branchless --version..."
+OUTPUT=$(./git-branchless --version 2>&1 || true)
+echo "Output: $OUTPUT"
+
+if echo "$OUTPUT" | grep -q "git-branchless"; then
+	echo "SUCCESS: git-branchless executed successfully"
+elif echo "$OUTPUT" | grep -q "No URL configured for platform"; then
+	echo "Expected platform error (not on linux-x64), but tool stub works"
+else
+	echo "FAIL: Unexpected output when executing git-branchless"
+	exit 1
+fi
+
+echo "Test passed!"

src/cli/generate/tool_stub.rs

@@ -444,7 +444,11 @@ impl ToolStub {
         if will_strip {
             let path = std::path::Path::new(&selected_exe);
             if let Ok(stripped) = path.strip_prefix(path.components().next().unwrap()) {
-                return Ok(stripped.to_string_lossy().to_string());
+                let stripped_str = stripped.to_string_lossy().to_string();
+                // Don't return empty string if stripping removed everything
+                if !stripped_str.is_empty() {
+                    return Ok(stripped_str);
+                }
             }
         }