fix: devbox code Remote SSH fixes + nix-ld + docs

README.md

@@ -142,6 +142,29 @@ ssh yourserver -t "devbox shell --name shared-api"
 
 ---
 
+## IDE Integration
+
+Use your local VS Code, Cursor, or Windsurf to edit code inside the sandbox — full IntelliSense, extensions, and debugging, all running in the isolated VM.
+
+```bash
+devbox code                       # Open VS Code into the sandbox
+devbox code --editor cursor       # Use Cursor instead
+devbox code --editor windsurf     # Use Windsurf
+devbox code myapp                 # Open a specific sandbox
+devbox code --path /workspace/src # Open a specific directory
+```
+
+Devbox automatically:
+1. Configures `~/.ssh/config` for the sandbox VM
+2. Refreshes the overlay layer (clears stale file handles)
+3. Launches the editor with Remote SSH pointed at `/workspace`
+
+Works with any editor that supports [Remote SSH](https://code.visualstudio.com/docs/remote/ssh) — VS Code, Cursor, Windsurf, and others.
+
+> **NixOS compatibility:** Devbox enables `nix-ld` in the VM so VS Code Server and other dynamically linked binaries run without issues.
+
+---
+
 ## Quick Start
 
 ### Prerequisites
@@ -309,6 +332,7 @@ All layer operations are also available in the **DevBox Management Panel** insid
 | `devbox destroy` | Remove a sandbox |
 | `devbox list` | List all sandboxes |
 | `devbox status` | Show detailed sandbox status |
+| `devbox code` | Open VS Code / Cursor into sandbox via Remote SSH |
 | `devbox use <name>` | Switch sandbox to current directory |
 | `devbox upgrade --tools <set>` | Add tools to a running sandbox |
 | `devbox packages` | Open TUI package manager |

nix/devbox-module.nix

@@ -50,6 +50,11 @@ in {
   virtualisation.docker.enable = lib.mkDefault (sets.container or false);
   services.tailscale.enable = lib.mkDefault (sets.network or false);
 
+  # ── Dynamic linker compat ─────────────────────────
+  # Required for VS Code Server, Cursor, and other dynamically linked
+  # binaries that expect a standard FHS layout (ld-linux, libc, etc.).
+  programs.nix-ld.enable = true;
+
   # ── Shell ──────────────────────────────────────────
   programs.zsh.enable = true;
   security.sudo.wheelNeedsPassword = lib.mkDefault false;

src/cli/code.rs

@@ -4,6 +4,7 @@ use clap::Args;
 use crate::runtime::cmd::run_cmd;
 use crate::runtime::SandboxStatus;
 use crate::sandbox::SandboxManager;
+use crate::sandbox::overlay;
 
 #[derive(Args, Debug)]
 pub struct CodeArgs {
@@ -36,6 +37,14 @@ pub async fn run(args: CodeArgs, manager: &SandboxManager) -> Result<()> {
         SandboxStatus::Unknown(s) => bail!("Sandbox '{name}' is in unknown state: {s}"),
     }
 
+    // Refresh overlay before opening editor to avoid stale file handles
+    if state.mount_mode != "writable" {
+        println!("Refreshing overlay layer...");
+        if let Err(e) = overlay::refresh(runtime.as_ref(), &name).await {
+            eprintln!("Warning: overlay refresh failed: {e}");
+        }
+    }
+
     let vm_name = format!("devbox-{name}");
     let ssh_host = format!("devbox-{name}");
 
@@ -67,7 +76,9 @@ async fn open_via_lima(
         );
     }
 
-    let ssh_config = result.stdout.trim().to_string();
+    // Lima's output has its own Host line (e.g. "Host lima-devbox-test2").
+    // Replace it with our ssh_host so VS Code can find the right config entry.
+    let ssh_config = rewrite_ssh_host(ssh_host, result.stdout.trim());
     write_ssh_config(ssh_host, &ssh_config)?;
 
     launch_editor(editor, ssh_host, path)
@@ -139,6 +150,21 @@ fn extract_incus_ip(json_output: &str) -> Result<String> {
     bail!("Could not find IP address for Incus VM. Is it running?")
 }
 
+/// Replace the `Host` line in an SSH config block with our desired host alias.
+fn rewrite_ssh_host(desired_host: &str, config: &str) -> String {
+    config
+        .lines()
+        .map(|line| {
+            if line.trim_start().starts_with("Host ") {
+                format!("Host {desired_host}")
+            } else {
+                line.to_string()
+            }
+        })
+        .collect::<Vec<_>>()
+        .join("\n")
+}
+
 /// Write or update an SSH config block in ~/.ssh/config for the devbox host.
 fn write_ssh_config(host: &str, config_block: &str) -> Result<()> {
     let home = dirs::home_dir().ok_or_else(|| anyhow::anyhow!("Cannot determine home directory"))?;
@@ -199,9 +225,11 @@ fn launch_editor(editor: &str, ssh_host: &str, path: &str) -> Result<()> {
 
     println!("Opening {editor} → {ssh_host}:{path}");
 
-    let remote_arg = format!("--remote=ssh-remote+{ssh_host}{path}");
+    let remote_arg = format!("ssh-remote+{ssh_host}");
     let status = std::process::Command::new(editor)
+        .arg("--remote")
         .arg(&remote_arg)
+        .arg(path)
         .status()
         .map_err(|e| anyhow::anyhow!("Failed to launch {editor}: {e}"))?;