fix: fall back to vendored bubblewrap when system bwrap lacks --argv0 (#15338)

## Why Fixes [#15283](https://github.com/openai/codex/issues/15283), where sandboxed tool calls fail on older distro `bubblewrap` builds because `/usr/bin/bwrap` does not understand `--argv0`. The upstream [bubblewrap v0.9.0 release notes](https://github.com/containers/bubblewrap/releases/tag/v0.9.0) explicitly call out `Add --argv0`. Flipping `use_legacy_landlock` globally works around that compatibility bug, but it also weakens the default Linux sandbox and breaks proxy-routed and split-policy cases called out in review. The follow-up Linux CI failure was in the new launcher test rather than the launcher logic: the fake `bwrap` helper stayed open for writing, so Linux would not exec it. This update also closes the user-visibility gap from review by surfacing the same startup warning when `/usr/bin/bwrap` is present but too old for `--argv0`, not only when it is missing. ## What Changed - keep `use_legacy_landlock` default-disabled - teach `codex-rs/linux-sandbox/src/launcher.rs` to fall back to the vendored bubblewrap build when `/usr/bin/bwrap` does not advertise `--argv0` support - add launcher tests for supported, unsupported, and missing system `bwrap` - write the fake `bwrap` test helper to a closed temp path so the supported-path launcher test works on Linux too - extend the startup warning path so Codex warns when `/usr/bin/bwrap` is missing or too old to support `--argv0` - mirror the warning/fallback wording across `codex-rs/linux-sandbox/README.md` and `codex-rs/core/README.md`, including that the fallback is the vendored bubblewrap compiled into the binary - cite the upstream `bubblewrap` release that introduced `--argv0` ## Verification - `bazel test --config=remote --platforms=//:rbe //codex-rs/linux-sandbox:linux-sandbox-unit-tests --test_filter=launcher::tests::prefers_system_bwrap_when_help_lists_argv0 --test_output=errors` - `cargo test -p codex-core system_bwrap_warning` - `cargo check -p codex-exec -p codex-tui -p codex-tui-app-server -p codex-app-server` - `just argument-comment-lint`
2026-07-01 00:31:56 +08:00 · 2026-03-23 09:46:51 -07:00
parent d807d44ae7
commit d1088158b8
9 changed files with 210 additions and 39 deletions
@@ -5582,16 +5582,69 @@ shell_tool = true
    Ok(())
 }

+#[cfg(target_os = "linux")]
 #[test]
-fn missing_system_bwrap_warning_matches_system_bwrap_presence() {
-    #[cfg(target_os = "linux")]
-    assert_eq!(
-        missing_system_bwrap_warning().is_some(),
-        !Path::new("/usr/bin/bwrap").is_file()
-    );
+fn system_bwrap_warning_reports_missing_system_bwrap() {
+    let warning = system_bwrap_warning_for_path(Path::new("/definitely/not/a/bwrap"))
+        .expect("missing system bwrap should emit a warning");

-    #[cfg(not(target_os = "linux"))]
-    assert!(missing_system_bwrap_warning().is_none());
+    assert!(warning.contains("could not find system bubblewrap"));
+}
+
+#[cfg(target_os = "linux")]
+#[test]
+fn system_bwrap_warning_reports_too_old_system_bwrap() {
+    let fake_bwrap = write_fake_bwrap(
+        r#"#!/bin/sh
+if [ "$1" = "--help" ]; then
+  echo 'usage: bwrap [OPTION...] COMMAND'
+  exit 0
+fi
+exit 1
+"#,
+    );
+    let fake_bwrap_path: &Path = fake_bwrap.as_ref();
+    let warning = system_bwrap_warning_for_path(fake_bwrap_path)
+        .expect("old system bwrap should emit a warning");
+
+    assert!(warning.contains("too old to support `--argv0`"));
+}
+
+#[cfg(target_os = "linux")]
+#[test]
+fn system_bwrap_warning_skips_supported_system_bwrap() {
+    let fake_bwrap = write_fake_bwrap(
+        r#"#!/bin/sh
+if [ "$1" = "--help" ]; then
+  echo '  --argv0 PROGRAM'
+  exit 0
+fi
+exit 1
+"#,
+    );
+    let fake_bwrap_path: &Path = fake_bwrap.as_ref();
+
+    assert_eq!(system_bwrap_warning_for_path(fake_bwrap_path), None);
+}
+
+#[cfg(not(target_os = "linux"))]
+#[test]
+fn system_bwrap_warning_is_disabled_off_linux() {
+    assert!(system_bwrap_warning().is_none());
+}
+
+#[cfg(target_os = "linux")]
+fn write_fake_bwrap(contents: &str) -> tempfile::TempPath {
+    use std::fs;
+    use std::os::unix::fs::PermissionsExt;
+    use tempfile::NamedTempFile;
+
+    // Linux rejects exec-ing a file that is still open for writing.
+    let path = NamedTempFile::new().expect("temp file").into_temp_path();
+    fs::write(&path, contents).expect("write fake bwrap");
+    let permissions = fs::Permissions::from_mode(0o755);
+    fs::set_permissions(&path, permissions).expect("chmod fake bwrap");
+    path
 }

 #[tokio::test]
@@ -96,6 +96,8 @@ use std::collections::HashMap;
 use std::io::ErrorKind;
 use std::path::Path;
 use std::path::PathBuf;
+#[cfg(target_os = "linux")]
+use std::process::Command;

 use crate::config::permissions::compile_permission_profile;
 use crate::config::permissions::get_readable_roots_required_for_codex_runtime;
@@ -153,21 +155,46 @@ const RESERVED_MODEL_PROVIDER_IDS: [&str; 3] = [
 ];

 #[cfg(target_os = "linux")]
-pub fn missing_system_bwrap_warning() -> Option<String> {
-    if Path::new(SYSTEM_BWRAP_PATH).is_file() {
-        None
-    } else {
-        Some(format!(
-            "Codex could not find system bubblewrap at {SYSTEM_BWRAP_PATH}. Please install bubblewrap with your package manager. Codex will use the vendored bubblewrap in the meantime."
-        ))
-    }
+pub fn system_bwrap_warning() -> Option<String> {
+    system_bwrap_warning_for_path(Path::new(SYSTEM_BWRAP_PATH))
 }

 #[cfg(not(target_os = "linux"))]
-pub fn missing_system_bwrap_warning() -> Option<String> {
+pub fn system_bwrap_warning() -> Option<String> {
    None
 }

+#[cfg(target_os = "linux")]
+fn system_bwrap_warning_for_path(system_bwrap_path: &Path) -> Option<String> {
+    if !system_bwrap_path.is_file() {
+        return Some(format!(
+            "Codex could not find system bubblewrap at {}. Please install bubblewrap with your package manager. Codex will use the vendored bubblewrap in the meantime.",
+            system_bwrap_path.display()
+        ));
+    }
+    if system_bwrap_supports_argv0(system_bwrap_path) {
+        return None;
+    }
+
+    Some(format!(
+        "Codex found system bubblewrap at {}, but it is too old to support `--argv0`. Please upgrade bubblewrap with your package manager. Codex will use the vendored bubblewrap in the meantime.",
+        system_bwrap_path.display()
+    ))
+}
+
+#[cfg(target_os = "linux")]
+fn system_bwrap_supports_argv0(system_bwrap_path: &Path) -> bool {
+    // bubblewrap added `--argv0` in v0.9.0:
+    // https://github.com/containers/bubblewrap/releases/tag/v0.9.0
+    let output = match Command::new(system_bwrap_path).arg("--help").output() {
+        Ok(output) => output,
+        Err(_) => return false,
+    };
+    let stdout = String::from_utf8_lossy(&output.stdout);
+    let stderr = String::from_utf8_lossy(&output.stderr);
+    stdout.contains("--argv0") || stderr.contains("--argv0")
+}
+
 fn resolve_sqlite_home_env(resolved_cwd: &Path) -> Option<PathBuf> {
    let raw = std::env::var(codex_state::SQLITE_HOME_ENV).ok()?;
    let trimmed = raw.trim();