diff --git a/CHANGELOG.md b/CHANGELOG.md
index d9df964d..3c98f94d 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,15 @@
+## 2.3.1 - Linux Compatibility Fix
+
+### 🐛 Bug Fixes
+
+- Resolved path handling issues on Linux systems for improved cross-platform compatibility
+
+---
+
+## What's Changed
+
+- fix: Fix to linux path issue by @AndyMik90 in 3276034
+
 ## 2.2.0 - 2025-12-17
 
 ### ✨ New Features
diff --git a/auto-claude/.env.example b/auto-claude/.env.example
index d794366d..cb2f2329 100644
--- a/auto-claude/.env.example
+++ b/auto-claude/.env.example
@@ -9,6 +9,16 @@ CLAUDE_CODE_OAUTH_TOKEN=your-oauth-token-here
 # Default: claude-opus-4-5-20251101
 # AUTO_BUILD_MODEL=claude-opus-4-5-20251101
 
+# =============================================================================
+# GIT/WORKTREE SETTINGS (OPTIONAL)
+# =============================================================================
+# Configure how Auto Claude handles git worktrees for isolated builds.
+
+# Default base branch for worktree creation (OPTIONAL)
+# If not set, Auto Claude will auto-detect main/master, or fall back to current branch.
+# Common values: main, master, develop
+# DEFAULT_BRANCH=main
+
 # =============================================================================
 # DEBUG MODE (OPTIONAL)
 # =============================================================================
diff --git a/auto-claude/core/worktree.py b/auto-claude/core/worktree.py
index 6afaea67..ef7e0f80 100644
--- a/auto-claude/core/worktree.py
+++ b/auto-claude/core/worktree.py
@@ -15,6 +15,7 @@ This allows:
 """
 
 import asyncio
+import os
 import re
 import shutil
 import subprocess
@@ -53,10 +54,55 @@ class WorktreeManager:
 
     def __init__(self, project_dir: Path, base_branch: str | None = None):
         self.project_dir = project_dir
-        self.base_branch = base_branch or self._get_current_branch()
+        self.base_branch = base_branch or self._detect_base_branch()
         self.worktrees_dir = project_dir / ".worktrees"
         self._merge_lock = asyncio.Lock()
 
+    def _detect_base_branch(self) -> str:
+        """
+        Detect the base branch for worktree creation.
+
+        Priority order:
+        1. DEFAULT_BRANCH environment variable
+        2. Auto-detect main/master (if they exist)
+        3. Fall back to current branch (with warning)
+
+        Returns:
+            The detected base branch name
+        """
+        # 1. Check for DEFAULT_BRANCH env var
+        env_branch = os.getenv("DEFAULT_BRANCH")
+        if env_branch:
+            # Verify the branch exists
+            result = subprocess.run(
+                ["git", "rev-parse", "--verify", env_branch],
+                cwd=self.project_dir,
+                capture_output=True,
+                text=True,
+            )
+            if result.returncode == 0:
+                return env_branch
+            else:
+                print(f"Warning: DEFAULT_BRANCH '{env_branch}' not found, auto-detecting...")
+
+        # 2. Auto-detect main/master
+        for branch in ["main", "master"]:
+            result = subprocess.run(
+                ["git", "rev-parse", "--verify", branch],
+                cwd=self.project_dir,
+                capture_output=True,
+                text=True,
+            )
+            if result.returncode == 0:
+                return branch
+
+        # 3. Fall back to current branch with warning
+        current = self._get_current_branch()
+        print(f"Warning: Could not find 'main' or 'master' branch.")
+        print(f"Warning: Using current branch '{current}' as base for worktree.")
+        print(f"Tip: Set DEFAULT_BRANCH=your-branch in .env to avoid this.")
+        return current
+
     def _get_current_branch(self) -> str:
         """Get the current git branch."""
         result = subprocess.run(
diff --git a/auto-claude/runners/spec_runner.py b/auto-claude/runners/spec_runner.py
index cc741c3d..436c1573 100644
--- a/auto-claude/runners/spec_runner.py
+++ b/auto-claude/runners/spec_runner.py
@@ -240,7 +240,7 @@ Examples:
             print()
 
             # Build the run.py command
-            run_script = Path(__file__).parent / "run.py"
+            run_script = Path(__file__).parent.parent / "run.py"
             run_cmd = [
                 sys.executable,
                 str(run_script),