This PR introduces a `codex-utils-cargo-bin` utility crate that
wraps/replaces our use of `assert_cmd::Command` and
`escargot::CargoBuild`.
As you can infer from the introduction of `buck_project_root()` in this
PR, I am attempting to make it possible to build Codex under
[Buck2](https://buck2.build) as well as `cargo`. With Buck2, I hope to
achieve faster incremental local builds (largely due to Buck2's
[dice](https://buck2.build/docs/insights_and_knowledge/modern_dice/)
build strategy, as well as benefits from its local build daemon) as well
as faster CI builds if we invest in remote execution and caching.
See
https://buck2.build/docs/getting_started/what_is_buck2/#why-use-buck2-key-advantages
for more details about the performance advantages of Buck2.
Buck2 enforces stronger requirements in terms of build and test
isolation. It discourages assumptions about absolute paths (which is key
to enabling remote execution). Because the `CARGO_BIN_EXE_*` environment
variables that Cargo provides are absolute paths (which
`assert_cmd::Command` reads), this is a problem for Buck2, which is why
we need this `codex-utils-cargo-bin` utility.
My WIP-Buck2 setup sets the `CARGO_BIN_EXE_*` environment variables
passed to a `rust_test()` build rule as relative paths.
`codex-utils-cargo-bin` will resolve these values to absolute paths,
when necessary.
---
[//]: # (BEGIN SAPLING FOOTER)
Stack created with [Sapling](https://sapling-scm.com). Best reviewed
with [ReviewStack](https://reviewstack.dev/openai/codex/pull/8496).
* #8498
* __->__ #8496
This PR introduces integration tests that run
[codex-shell-tool-mcp](https://www.npmjs.com/package/@openai/codex-shell-tool-mcp)
as a user would. Note that this requires running our fork of Bash, so we
introduce a [DotSlash](https://dotslash-cli.com/) file for `bash` so
that we can run the integration tests on multiple platforms without
having to check the binaries into the repository. (As noted in the
DotSlash file, it is slightly more heavyweight than necessary, which may
be worth addressing as disk space in CI is limited:
https://github.com/openai/codex/pull/7678.)
To start, this PR adds two tests:
- `list_tools()` makes the `list_tools` request to the MCP server and
verifies we get the expected response
- `accept_elicitation_for_prompt_rule()` defines a `prefix_rule()` with
`decision="prompt"` and verifies the elicitation flow works as expected
Though the `accept_elicitation_for_prompt_rule()` test **only works on
Linux**, as this PR reveals that there are currently issues when running
the Bash fork in a read-only sandbox on Linux. This will have to be
fixed in a follow-up PR.
Incidentally, getting this test run to correctly on macOS also requires
a recent fix we made to `brew` that hasn't hit a mainline release yet,
so getting CI green in this PR required
https://github.com/openai/codex/pull/7680.
Previously, we were running into an issue where we would run the `shell`
tool call with a timeout of 10s, but it fired an elicitation asking for
user approval, the time the user took to respond to the elicitation was
counted agains the 10s timeout, so the `shell` tool call would fail with
a timeout error unless the user is very fast!
This PR addresses this issue by introducing a "stopwatch" abstraction
that is used to manage the timeout. The idea is:
- `Stopwatch::new()` is called with the _real_ timeout of the `shell`
tool call.
- `process_exec_tool_call()` is called with the `Cancellation` variant
of `ExecExpiration` because it should not manage its own timeout in this
case
- the `Stopwatch` expiration is wired up to the `cancel_rx` passed to
`process_exec_tool_call()`
- when an elicitation for the `shell` tool call is received, the
`Stopwatch` pauses
- because it is possible for multiple elicitations to arrive
concurrently, it keeps track of the number of "active pauses" and does
not resume until that counter goes down to zero
I verified that I can test the MCP server using
`@modelcontextprotocol/inspector` and specify `git status` as the
`command` with a timeout of 500ms and that the elicitation pops up and I
have all the time in the world to respond whereas previous to this PR,
that would not have been possible.
---
[//]: # (BEGIN SAPLING FOOTER)
Stack created with [Sapling](https://sapling-scm.com). Best reviewed
with [ReviewStack](https://reviewstack.dev/openai/codex/pull/6973).
* #7005
* __->__ #6973
* #6972
This PR reorganizes things slightly so that:
- Instead of a single multitool executable, `codex-exec-server`, we now
have two executables:
- `codex-exec-mcp-server` to launch the MCP server
- `codex-execve-wrapper` is the `execve(2)` wrapper to use with the
`BASH_EXEC_WRAPPER` environment variable
- `BASH_EXEC_WRAPPER` must be a single executable: it cannot be a
command string composed of an executable with args (i.e., it no longer
adds the `escalate` subcommand, as before)
- `codex-exec-mcp-server` takes `--bash` and `--execve` as options.
Though if `--execve` is not specified, the MCP server will check the
directory containing `std::env::current_exe()` and attempt to use the
file named `codex-execve-wrapper` within it. In development, this works
out since these executables are side-by-side in the `target/debug`
folder.
With respect to testing, this also fixes an important bug in
`dummy_exec_policy()`, as I was using `ends_with()` as if it applied to
a `String`, but in this case, it is used with a `&Path`, so the
semantics are slightly different.
Putting this all together, I was able to test this by running the
following:
```
~/code/codex/codex-rs$ npx @modelcontextprotocol/inspector \
./target/debug/codex-exec-mcp-server --bash ~/code/bash/bash
```
If I try to run `git status` in `/Users/mbolin/code/codex` via the
`shell` tool from the MCP server:
<img width="1589" height="1335" alt="image"
src="https://github.com/user-attachments/assets/9db6aea8-7fbc-4675-8b1f-ec446685d6c4"
/>
then I get prompted with the following elicitation, as expected:
<img width="1589" height="1335" alt="image"
src="https://github.com/user-attachments/assets/21b68fe0-494d-4562-9bad-0ddc55fc846d"
/>
Though a current limitation is that the `shell` tool defaults to a
timeout of 10s, which means I only have 10s to respond to the
elicitation. Ideally, the time spent waiting for a response from a human
should not count against the timeout for the command execution. I will
address this in a subsequent PR.
---
Note `~/code/bash/bash` was created by doing:
```
cd ~/code
git clone https://github.com/bminor/bash
cd bash
git checkout a8a1c2fac029404d3f42cd39f5a20f24b6e4fe4b
<apply the patch below>
./configure
make
```
The patch:
```
diff --git a/execute_cmd.c b/execute_cmd.c
index 070f5119..d20ad2b9 100644
--- a/execute_cmd.c
+++ b/execute_cmd.c
@@ -6129,6 +6129,19 @@ shell_execve (char *command, char **args, char **env)
char sample[HASH_BANG_BUFSIZ];
size_t larray;
+ char* exec_wrapper = getenv("BASH_EXEC_WRAPPER");
+ if (exec_wrapper && *exec_wrapper && !whitespace (*exec_wrapper))
+ {
+ char *orig_command = command;
+
+ larray = strvec_len (args);
+
+ memmove (args + 2, args, (++larray) * sizeof (char *));
+ args[0] = exec_wrapper;
+ args[1] = orig_command;
+ command = exec_wrapper;
+ }
+
```
This PR introduces an extra layer of abstraction to prepare us for the
migration to execpolicy2:
- introduces a new trait, `EscalationPolicy`, whose `determine_action()`
method is responsible for producing the `EscalateAction`
- the existing `ExecPolicy` typedef is changed to return an intermediate
`ExecPolicyOutcome` instead of `EscalateAction`
- the default implementation of `EscalationPolicy`,
`McpEscalationPolicy`, composes `ExecPolicy`
- the `ExecPolicyOutcome` includes `codex_execpolicy2::Decision`, which
has a `Prompt` variant
- when `McpEscalationPolicy` gets `Decision::Prompt` back from
`ExecPolicy`, it prompts the user via an MCP elicitation and maps the
result into an `ElicitationAction`
- now that the end user can reply to an elicitation with `Decline` or
`Cancel`, we introduce a new variant, `EscalateAction::Deny`, which the
client handles by returning exit code `1` without running anything
Note the way the elicitation is created is still not quite right, but I
will fix that once we have things running end-to-end for real in a
follow-up PR.
