diff --git a/README.md b/README.md
index f2aecb6f69c..2dc86be1174 100644
--- a/README.md
+++ b/README.md
@@ -119,6 +119,23 @@ aider --model sonnet --api-key anthropic=<key>
 aider --model o3-mini --api-key openai=<key>
 ```
 
+### Configuration
+
+Create a `.aider.conf.yml` file to configure model aliases and other settings:
+
+```yaml
+# Use a list to define multiple aliases
+alias:
+  - "fast:gpt-4o-mini"
+  - "smart:o3-mini"
+  - "hacker:claude-3-sonnet-20240229"
+
+# Default model
+model: "gpt-4o-mini"
+```
+
+> **Note:** YAML does not support repeated keys. Always use a list format for multiple aliases.
+
 See the [installation instructions](https://aider.chat/docs/install.html) and [usage documentation](https://aider.chat/docs/usage.html) for more details.
 
 ## More Information
diff --git a/aider/args.py b/aider/args.py
index 5b3fdf07faf..bbfa2915f34 100644
--- a/aider/args.py
+++ b/aider/args.py
@@ -392,6 +392,12 @@ def get_parser(default_config_files, git_root):
             " see https://pygments.org/styles for available themes)"
         ),
     )
+    group.add_argument(
+        "--code-theme-no-background",
+        action="store_true",
+        help="Disable background colors in code theme (default: False)",
+        default=False,
+    )
     group.add_argument(
         "--show-diffs",
         action="store_true",
diff --git a/aider/io.py b/aider/io.py
index ed6f22d51ae..9411b29b96d 100644
--- a/aider/io.py
+++ b/aider/io.py
@@ -252,6 +252,7 @@ def __init__(
         completion_menu_current_color=None,
         completion_menu_current_bg_color=None,
         code_theme="default",
+        code_theme_no_background=False,
         encoding="utf-8",
         line_endings="platform",
         dry_run=False,
@@ -297,6 +298,7 @@ def __init__(
         )
 
         self.code_theme = code_theme
+        self.code_theme_no_background = code_theme_no_background
 
         self.input = input
         self.output = output
@@ -1015,6 +1017,7 @@ def get_assistant_mdstream(self):
         mdargs = dict(
             style=self.assistant_output_color,
             code_theme=self.code_theme,
+            code_theme_no_background=self.code_theme_no_background,
             inline_code_lexer="text",
         )
         mdStream = MarkdownStream(mdargs=mdargs)
diff --git a/aider/main.py b/aider/main.py
index afb3f836624..f1b6f699e2a 100644
--- a/aider/main.py
+++ b/aider/main.py
@@ -140,14 +140,25 @@ def setup_git(git_root, io):
 
     if user_name and user_email:
         return repo.working_tree_dir
-
-    with repo.config_writer() as git_config:
-        if not user_name:
-            git_config.set_value("user", "name", "Your Name")
-            io.tool_warning('Update git name with: git config user.name "Your Name"')
-        if not user_email:
-            git_config.set_value("user", "email", "you@example.com")
-            io.tool_warning('Update git email with: git config user.email "you@example.com"')
+    
+    try:
+        with repo.config_writer() as git_config:
+            if not user_name:
+                git_config.set_value("user", "name", "Your Name")
+                io.tool_warning('Update git name with: git config user.name "Your Name"')
+            if not user_email:
+                git_config.set_value("user", "email", "you@example.com")
+                io.tool_warning('Update git email with: git config user.email "you@example.com"')
+    except (OSError, PermissionError) as e:
+        io.tool_warning(
+            f"Warning: Could not write to git config: {e}\n"
+            f"This may be due to network drive permissions or file locking issues.\n"
+            f"You may need to manually set git config values using:\n"
+            f"git config user.name \"Your Name\"\n"
+            f"git config user.email \"you@example.com\""
+        )
+        # Continue without modifying config, in read-only mode
+        pass
 
     return repo.working_tree_dir
 
@@ -542,6 +553,11 @@ def main(argv=None, input=None, output=None, force_git_root=None, return_coder=F
         args.tool_warning_color = "#FFA500"
         args.assistant_output_color = "blue"
         args.code_theme = "default"
+        # Clear background colors for light mode
+        args.completion_menu_bg_color = None
+        args.completion_menu_current_bg_color = None
+        # Override Pygments theme to disable backgrounds
+        args.code_theme_no_background = True
 
     if return_coder and args.yes_always is None:
         args.yes_always = True
@@ -566,6 +582,7 @@ def get_io(pretty):
             completion_menu_current_bg_color=args.completion_menu_current_bg_color,
             assistant_output_color=args.assistant_output_color,
             code_theme=args.code_theme,
+            code_theme_no_background=args.code_theme_no_background,
             dry_run=args.dry_run,
             encoding=args.encoding,
             line_endings=args.line_endings,
diff --git a/aider/md_renderer.py b/aider/md_renderer.py
new file mode 100644
index 00000000000..7debc6cccfb
--- /dev/null
+++ b/aider/md_renderer.py
@@ -0,0 +1,28 @@
+from rich.markdown import Markdown, Padding
+from rich.syntax import Syntax
+
+from .theme_utils import get_code_theme
+
+class CustomMarkdown(Markdown):
+    """Custom Markdown renderer that handles code block backgrounds"""
+    
+    def __init__(self, text, code_theme="default", code_theme_no_background=False, **kwargs):
+        self.code_theme_name = code_theme
+        self.code_theme_no_background = code_theme_no_background
+        super().__init__(text, **kwargs)
+
+    def render_code_block(self, block, width):
+        """Render a code block with optional background removal."""
+        code = block.text.rstrip()
+        lexer = block.lexer_name if hasattr(block, "lexer_name") else "default"
+        
+        theme = get_code_theme(self.code_theme_name, self.code_theme_no_background)
+        syntax = Syntax(
+            code,
+            lexer,
+            theme=theme,
+            word_wrap=False,
+            padding=0,
+            background_color=None if self.code_theme_no_background else "default",
+        )
+        return Padding(syntax, pad=(0, 0))
\ No newline at end of file
diff --git a/aider/mdstream.py b/aider/mdstream.py
index 774b247c2be..1e8b40aac2c 100755
--- a/aider/mdstream.py
+++ b/aider/mdstream.py
@@ -6,11 +6,13 @@
 from rich import box
 from rich.console import Console
 from rich.live import Live
-from rich.markdown import CodeBlock, Heading, Markdown
+from rich.markdown import CodeBlock, Heading
 from rich.panel import Panel
 from rich.syntax import Syntax
 from rich.text import Text
 
+from .md_renderer import CustomMarkdown
+
 from aider.dump import dump  # noqa: F401
 
 _text_prefix = """
@@ -131,7 +133,7 @@ def _render_markdown_to_lines(self, text):
         # Render the markdown to a string buffer
         string_io = io.StringIO()
         console = Console(file=string_io, force_terminal=True)
-        markdown = NoInsetMarkdown(text, **self.mdargs)
+        markdown = CustomMarkdown(text, **self.mdargs)
         console.print(markdown)
         output = string_io.getvalue()
 
diff --git a/aider/theme_utils.py b/aider/theme_utils.py
new file mode 100644
index 00000000000..646c43ab502
--- /dev/null
+++ b/aider/theme_utils.py
@@ -0,0 +1,34 @@
+from pygments.style import Style as PygmentsStyle
+from pygments.util import ClassNotFound
+from pygments.styles import get_style_by_name
+
+
+class NoBackgroundStyle(PygmentsStyle):
+    """A style wrapper that removes background colors from another style."""
+
+    def __init__(self, base_style):
+        # Get the base style's colors and settings
+        self.styles = base_style.styles.copy()
+        # Remove background colors from all token styles
+        for token, style_string in self.styles.items():
+            if style_string:
+                # Split style into parts
+                parts = style_string.split()
+                # Filter out any bg:color settings
+                parts = [p for p in parts if not p.startswith('bg:')]
+                self.styles[token] = ' '.join(parts)
+
+
+def get_code_theme(theme_name, no_background=False):
+    """Get a Pygments style, optionally without backgrounds."""
+    try:
+        base_style = get_style_by_name(theme_name)
+        if no_background:
+            return NoBackgroundStyle(base_style)
+        return base_style
+    except ClassNotFound:
+        # Fallback to default style
+        base_style = get_style_by_name('default')
+        if no_background:
+            return NoBackgroundStyle(base_style)
+        return base_style
\ No newline at end of file
diff --git a/aider/utils.py b/aider/utils.py
index 834ffa1953d..0f90bc51d93 100644
--- a/aider/utils.py
+++ b/aider/utils.py
@@ -95,8 +95,14 @@ def is_image_file(file_name):
 
 def safe_abs_path(res):
     "Gives an abs path, which safely returns a full (not 8.3) windows path"
-    res = Path(res).resolve()
-    return str(res)
+    try:
+        res = Path(res).resolve(strict=False)
+        return str(res)
+    except RuntimeError as e:
+        if "Symlink loop" in str(e):
+            # If we encounter a symlink loop, return the absolute path without resolving symlinks
+            return str(Path(res).absolute())
+        raise
 
 
 def format_content(role, content):
diff --git a/tests/basic/test_git_config_network.py b/tests/basic/test_git_config_network.py
new file mode 100644
index 00000000000..6ff775dd6af
--- /dev/null
+++ b/tests/basic/test_git_config_network.py
@@ -0,0 +1,46 @@
+import os
+from pathlib import Path
+from unittest import TestCase
+from unittest.mock import patch, MagicMock
+
+import git
+
+from aider.io import InputOutput
+from aider.main import setup_git
+from aider.utils import GitTemporaryDirectory
+
+
+class TestGitConfigNetworkDrive(TestCase):
+    def setUp(self):
+        self.tempdir = GitTemporaryDirectory()
+        self.old_cwd = os.getcwd()
+        os.chdir(self.tempdir.name)
+
+    def tearDown(self):
+        os.chdir(self.old_cwd)
+        self.tempdir.cleanup()
+
+    def test_setup_git_with_permission_error(self):
+        """Test that setup_git handles permission errors gracefully"""
+        io = InputOutput(pretty=False, yes=True)
+
+        # Create a mock repo that raises PermissionError on config_writer
+        mock_repo = MagicMock(spec=git.Repo)
+        mock_config_writer = MagicMock()
+        mock_config_writer.__enter__ = MagicMock(side_effect=PermissionError("Permission denied"))
+        mock_repo.config_writer.return_value = mock_config_writer
+        
+        # Create a test working directory to return
+        test_dir = str(Path(self.tempdir.name).resolve())
+        mock_repo.working_tree_dir = test_dir
+
+        # Mock git.Repo to return our mock
+        with patch('git.Repo', return_value=mock_repo):
+            result = setup_git(test_dir, io)
+
+        # Verify setup_git completes and returns working directory despite error
+        self.assertEqual(result, test_dir)
+
+        # Verify warning was shown
+        warnings = [call[0][0] for call in io.tool_warning.call_args_list]
+        self.assertTrue(any("Could not write to git config" in warning for warning in warnings))
\ No newline at end of file
diff --git a/tests/test_utils_symlinks.py b/tests/test_utils_symlinks.py
new file mode 100644
index 00000000000..4a933995bf9
--- /dev/null
+++ b/tests/test_utils_symlinks.py
@@ -0,0 +1,60 @@
+import os
+import unittest
+from pathlib import Path
+import tempfile
+
+from aider.utils import safe_abs_path
+
+
+class TestUtilsSymlinks(unittest.TestCase):
+    def setUp(self):
+        # Create a temporary directory for our tests
+        self.test_dir = tempfile.mkdtemp()
+        self.orig_cwd = os.getcwd()
+        os.chdir(self.test_dir)
+
+    def tearDown(self):
+        # Clean up
+        os.chdir(self.orig_cwd)
+        try:
+            import shutil
+            shutil.rmtree(self.test_dir)
+        except:
+            pass
+
+    def test_safe_abs_path_normal(self):
+        """Test safe_abs_path with a normal path"""
+        test_file = Path(self.test_dir) / "test.txt"
+        test_file.touch()
+        result = safe_abs_path(test_file)
+        self.assertEqual(str(test_file.resolve()), result)
+
+    def test_safe_abs_path_symlink_loop(self):
+        """Test safe_abs_path with a circular symlink"""
+        # Create a circular symlink
+        link1 = Path(self.test_dir) / "link1"
+        link2 = Path(self.test_dir) / "link2"
+        
+        # Create the first link pointing to the second
+        os.symlink("link2", str(link1))
+        # Create the second link pointing back to the first
+        os.symlink("link1", str(link2))
+
+        # Test that safe_abs_path handles the symlink loop gracefully
+        result = safe_abs_path(link1)
+        self.assertTrue(result.endswith("link1"))
+        self.assertTrue(os.path.isabs(result))
+
+    def test_safe_abs_path_nonexistent(self):
+        """Test safe_abs_path with a non-existent path"""
+        nonexistent = Path(self.test_dir) / "nonexistent"
+        result = safe_abs_path(nonexistent)
+        self.assertTrue(os.path.isabs(result))
+        self.assertTrue(result.endswith("nonexistent"))
+
+    def test_safe_abs_path_relative(self):
+        """Test safe_abs_path with a relative path"""
+        rel_path = "relative/path"
+        result = safe_abs_path(rel_path)
+        self.assertTrue(os.path.isabs(result))
+        self.assertTrue(result.endswith(rel_path.replace("/", os.path.sep)))
\ No newline at end of file