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.
