fix: declare test path relative to $CARGO_MANIFEST_DIR

AGENTS.md

@@ -77,6 +77,12 @@ If you don’t have the tool:
 - Prefer deep equals comparisons whenever possible. Perform `assert_eq!()` on entire objects, rather than individual fields.
 - Avoid mutating process environment in tests; prefer passing environment-derived flags or dependencies from above.
 
+### Spawning workspace binaries in tests (Cargo vs Buck2)
+
+- Prefer `codex_utils_cargo_bin::cargo_bin("...")` over `assert_cmd::Command::cargo_bin(...)` or `escargot` when tests need to spawn first-party binaries.
+  - Under Buck2, `CARGO_BIN_EXE_*` may be project-relative (e.g. `buck-out/...`), which breaks if a test changes its working directory. `codex_utils_cargo_bin::cargo_bin` resolves to an absolute path first.
+- When locating fixture files under Buck2, avoid `env!("CARGO_MANIFEST_DIR")` (Buck codegen sets it to `"."`). Prefer deriving paths from `codex_utils_cargo_bin::buck_project_root()` when needed.
+
 ### Integration tests (core)
 
 - Prefer the utilities in `core_test_support::responses` when writing end-to-end Codex tests.

codex-rs/Cargo.toml

@@ -36,6 +36,7 @@ members = [
     "tui",
     "tui2",
     "utils/absolute-path",
+    "utils/cargo-bin",
     "utils/git",
     "utils/cache",
     "utils/image",
@@ -93,6 +94,7 @@ codex-tui = { path = "tui" }
 codex-tui2 = { path = "tui2" }
 codex-utils-absolute-path = { path = "utils/absolute-path" }
 codex-utils-cache = { path = "utils/cache" }
+codex-utils-cargo-bin = { path = "utils/cargo-bin" }
 codex-utils-image = { path = "utils/image" }
 codex-utils-json-to-toml = { path = "utils/json-to-toml" }
 codex-utils-pty = { path = "utils/pty" }

codex-rs/app-server/Cargo.toml

@@ -48,7 +48,6 @@ uuid = { workspace = true, features = ["serde", "v7"] }
 
 [dev-dependencies]
 app_test_support = { workspace = true }
-assert_cmd = { workspace = true }
 base64 = { workspace = true }
 core_test_support = { workspace = true }
 mcp-types = { workspace = true }

codex-rs/app-server/tests/common/Cargo.toml

@@ -9,12 +9,12 @@ path = "lib.rs"
 
 [dependencies]
 anyhow = { workspace = true }
-assert_cmd = { workspace = true }
 base64 = { workspace = true }
 chrono = { workspace = true }
 codex-app-server-protocol = { workspace = true }
 codex-core = { workspace = true, features = ["test-support"] }
 codex-protocol = { workspace = true }
+codex-utils-cargo-bin = { workspace = true }
 serde = { workspace = true }
 serde_json = { workspace = true }
 tokio = { workspace = true, features = [

codex-rs/app-server/tests/common/mcp_process.rs

@@ -11,7 +11,6 @@ use tokio::process::ChildStdin;
 use tokio::process::ChildStdout;
 
 use anyhow::Context;
-use assert_cmd::prelude::*;
 use codex_app_server_protocol::AddConversationListenerParams;
 use codex_app_server_protocol::ArchiveConversationParams;
 use codex_app_server_protocol::CancelLoginAccountParams;
@@ -49,7 +48,6 @@ use codex_app_server_protocol::ThreadResumeParams;
 use codex_app_server_protocol::ThreadStartParams;
 use codex_app_server_protocol::TurnInterruptParams;
 use codex_app_server_protocol::TurnStartParams;
-use std::process::Command as StdCommand;
 use tokio::process::Command;
 
 pub struct McpProcess {
@@ -78,12 +76,8 @@ impl McpProcess {
         codex_home: &Path,
         env_overrides: &[(&str, Option<&str>)],
     ) -> anyhow::Result<Self> {
-        // Use assert_cmd to locate the binary path and then switch to tokio::process::Command
-        let std_cmd = StdCommand::cargo_bin("codex-app-server")
-            .context("should find binary for codex-mcp-server")?;
-
-        let program = std_cmd.get_program().to_owned();
-
+        let program = codex_utils_cargo_bin::cargo_bin("codex-app-server")
+            .context("should find binary for codex-app-server")?;
         let mut cmd = Command::new(program);
 
         cmd.stdin(Stdio::piped());

codex-rs/apply-patch/Cargo.toml

@@ -25,5 +25,6 @@ tree-sitter-bash = { workspace = true }
 [dev-dependencies]
 assert_cmd = { workspace = true }
 assert_matches = { workspace = true }
+codex-utils-cargo-bin = { workspace = true }
 pretty_assertions = { workspace = true }
 tempfile = { workspace = true }

codex-rs/apply-patch/tests/suite/cli.rs

@@ -1,8 +1,13 @@
-use assert_cmd::prelude::*;
+use assert_cmd::Command;
 use std::fs;
-use std::process::Command;
 use tempfile::tempdir;
 
+fn apply_patch_command() -> anyhow::Result<Command> {
+    Ok(Command::new(codex_utils_cargo_bin::cargo_bin(
+        "apply_patch",
+    )?))
+}
+
 #[test]
 fn test_apply_patch_cli_add_and_update() -> anyhow::Result<()> {
     let tmp = tempdir()?;
@@ -16,8 +21,7 @@ fn test_apply_patch_cli_add_and_update() -> anyhow::Result<()> {
 +hello
 *** End Patch"#
     );
-    Command::cargo_bin("apply_patch")
-        .expect("should find apply_patch binary")
+    apply_patch_command()?
         .arg(add_patch)
         .current_dir(tmp.path())
         .assert()
@@ -34,8 +38,7 @@ fn test_apply_patch_cli_add_and_update() -> anyhow::Result<()> {
 +world
 *** End Patch"#
     );
-    Command::cargo_bin("apply_patch")
-        .expect("should find apply_patch binary")
+    apply_patch_command()?
         .arg(update_patch)
         .current_dir(tmp.path())
         .assert()
@@ -59,10 +62,9 @@ fn test_apply_patch_cli_stdin_add_and_update() -> anyhow::Result<()> {
 +hello
 *** End Patch"#
     );
-    let mut cmd =
-        assert_cmd::Command::cargo_bin("apply_patch").expect("should find apply_patch binary");
-    cmd.current_dir(tmp.path());
-    cmd.write_stdin(add_patch)
+    apply_patch_command()?
+        .current_dir(tmp.path())
+        .write_stdin(add_patch)
         .assert()
         .success()
         .stdout(format!("Success. Updated the following files:\nA {file}\n"));
@@ -77,10 +79,9 @@ fn test_apply_patch_cli_stdin_add_and_update() -> anyhow::Result<()> {
 +world
 *** End Patch"#
     );
-    let mut cmd =
-        assert_cmd::Command::cargo_bin("apply_patch").expect("should find apply_patch binary");
-    cmd.current_dir(tmp.path());
-    cmd.write_stdin(update_patch)
+    apply_patch_command()?
+        .current_dir(tmp.path())
+        .write_stdin(update_patch)
         .assert()
         .success()
         .stdout(format!("Success. Updated the following files:\nM {file}\n"));

codex-rs/apply-patch/tests/suite/scenarios.rs

@@ -1,4 +1,3 @@
-use assert_cmd::prelude::*;
 use pretty_assertions::assert_eq;
 use std::collections::BTreeMap;
 use std::fs;
@@ -9,7 +8,8 @@ use tempfile::tempdir;
 
 #[test]
 fn test_apply_patch_scenarios() -> anyhow::Result<()> {
-    for scenario in fs::read_dir("tests/fixtures/scenarios")? {
+    let scenarios_dir = Path::new(env!("CARGO_MANIFEST_DIR")).join("tests/fixtures/scenarios");
+    for scenario in fs::read_dir(scenarios_dir)? {
         let scenario = scenario?;
         let path = scenario.path();
         if path.is_dir() {
@@ -36,7 +36,7 @@ fn run_apply_patch_scenario(dir: &Path) -> anyhow::Result<()> {
     // Run apply_patch in the temporary directory. We intentionally do not assert
     // on the exit status here; the scenarios are specified purely in terms of
     // final filesystem state, which we compare below.
-    Command::cargo_bin("apply_patch")?
+    Command::new(codex_utils_cargo_bin::cargo_bin("apply_patch")?)
         .arg(patch)
         .current_dir(tmp.path())
         .output()?;
@@ -82,11 +82,15 @@ fn snapshot_dir_recursive(
             continue;
         };
         let rel = stripped.to_path_buf();
-        let file_type = entry.file_type()?;
-        if file_type.is_dir() {
+
+        // Under Buck2, files in `__srcs` are often materialized as symlinks.
+        // Use `metadata()` (follows symlinks) so our fixture snapshots work
+        // under both Cargo and Buck2.
+        let metadata = fs::metadata(&path)?;
+        if metadata.is_dir() {
             entries.insert(rel.clone(), Entry::Dir);
             snapshot_dir_recursive(base, &path, entries)?;
-        } else if file_type.is_file() {
+        } else if metadata.is_file() {
             let contents = fs::read(&path)?;
             entries.insert(rel, Entry::File(contents));
         }
@@ -98,12 +102,14 @@ fn copy_dir_recursive(src: &Path, dst: &Path) -> anyhow::Result<()> {
     for entry in fs::read_dir(src)? {
         let entry = entry?;
         let path = entry.path();
-        let file_type = entry.file_type()?;
         let dest_path = dst.join(entry.file_name());
-        if file_type.is_dir() {
+
+        // See note in `snapshot_dir_recursive` about Buck2 symlink trees.
+        let metadata = fs::metadata(&path)?;
+        if metadata.is_dir() {
             fs::create_dir_all(&dest_path)?;
             copy_dir_recursive(&path, &dest_path)?;
-        } else if file_type.is_file() {
+        } else if metadata.is_file() {
             if let Some(parent) = dest_path.parent() {
                 fs::create_dir_all(parent)?;
             }

codex-rs/apply-patch/tests/suite/tool.rs

@@ -5,13 +5,13 @@ use std::path::Path;
 use tempfile::tempdir;
 
 fn run_apply_patch_in_dir(dir: &Path, patch: &str) -> anyhow::Result<assert_cmd::assert::Assert> {
-    let mut cmd = Command::cargo_bin("apply_patch")?;
+    let mut cmd = Command::new(codex_utils_cargo_bin::cargo_bin("apply_patch")?);
     cmd.current_dir(dir);
     Ok(cmd.arg(patch).assert())
 }
 
 fn apply_patch_command(dir: &Path) -> anyhow::Result<Command> {
-    let mut cmd = Command::cargo_bin("apply_patch")?;
+    let mut cmd = Command::new(codex_utils_cargo_bin::cargo_bin("apply_patch")?);
     cmd.current_dir(dir);
     Ok(cmd)
 }

codex-rs/cli/Cargo.toml

@@ -60,6 +60,7 @@ codex_windows_sandbox = { package = "codex-windows-sandbox", path = "../windows-
 [dev-dependencies]
 assert_cmd = { workspace = true }
 assert_matches = { workspace = true }
+codex-utils-cargo-bin = { workspace = true }
 predicates = { workspace = true }
 pretty_assertions = { workspace = true }
 tempfile = { workspace = true }

codex-rs/cli/tests/execpolicy.rs

@@ -24,7 +24,7 @@ prefix_rule(
 "#,
     )?;
 
-    let output = Command::cargo_bin("codex")?
+    let output = Command::new(codex_utils_cargo_bin::cargo_bin("codex")?)
         .env("CODEX_HOME", codex_home.path())
         .args([
             "execpolicy",

codex-rs/cli/tests/mcp_add_remove.rs

@@ -8,7 +8,7 @@ use pretty_assertions::assert_eq;
 use tempfile::TempDir;
 
 fn codex_command(codex_home: &Path) -> Result<assert_cmd::Command> {
-    let mut cmd = assert_cmd::Command::cargo_bin("codex")?;
+    let mut cmd = assert_cmd::Command::new(codex_utils_cargo_bin::cargo_bin("codex")?);
     cmd.env("CODEX_HOME", codex_home);
     Ok(cmd)
 }