## Why
Shell execution refactoring in `exec-server` had become split between
duplicated code paths, which blocked a clean introduction of the new
reusable shell escalation flow. This commit creates a dedicated
foundation crate so later shell tooling changes can share one
implementation.
## What changed
- Added the `codex-shell-escalation` crate and moved the core escalation
pieces (`mcp` protocol/socket/session flow, policy glue) that were
previously in `exec-server` into it.
- Normalized `exec-server` Unix structure under a dedicated `unix`
module layout and kept non-Unix builds narrow.
- Wired crate/build metadata so `shell-escalation` is a first-class
workspace dependency for follow-on integration work.
## Verification
- Built and linted the stack at this commit point with `just clippy`.
[//]: # (BEGIN SAPLING FOOTER)
Stack created with [Sapling](https://sapling-scm.com). Best reviewed
with [ReviewStack](https://reviewstack.dev/openai/codex/pull/12556).
* #12584
* #12583
* __->__ #12556
## Summary
Improve Bazel CI failure diagnostics by printing the tail of each failed
target’s test.log directly in the GitHub Actions output.
Today, when a large Bazel test target fails (for example tests of
`codex-core`), the workflow often only shows a target-level Exit 101
plus a path to Bazel’s test.log. That makes it hard to see the actual
failing Rust test and panic without digging into artifacts or
reproducing locally.
This change makes the workflow automatically surface that information
inline.
## What Changed
In .github/workflows/bazel.yml:
- Capture Bazel console output via tee
- Preserve the Bazel exit code when piping (PIPESTATUS[0])
- On failure:
- Parse failed Bazel test targets from FAIL: //... lines
- Resolve Bazel test log directory via bazel info bazel-testlogs
- Print tail -n 200 for each failed target’s test.log
- Group each target’s output in GitHub Actions logs (::group::)
## Bonus
Disable `experimental_remote_repo_contents_cache` to prevent "Permission
Denied"
Summary
- mark `output-last-message` as a global exec flag so it can follow
subcommands like `resume`
- add regression tests in both `cli` and `exec` crates verifying the
flag order works when invoking `resume`
Fixes#12538
## Why
The current escalate path in `codex-rs/exec-server` still had policy
creation coupled to MCP details, which makes it hard to reuse the shell
execution flow outside the MCP server. This change is part of a broader
goal to split MCP-specific behavior from shared escalation execution so
other handlers (for example a future `ShellCommandHandler`) can reuse it
without depending on MCP request context types.
## What changed
- Added a new `EscalationPolicyFactory` abstraction in `mcp.rs`:
- `crate`-relative path: `codex-rs/exec-server/src/posix/mcp.rs`
-
https://github.com/openai/codex/blob/main/codex-rs/exec-server/src/posix/mcp.rs#L87-L107
- Made `run_escalate_server` in `mcp.rs` accept a policy factory instead
of constructing `McpEscalationPolicy` directly.
-
https://github.com/openai/codex/blob/main/codex-rs/exec-server/src/posix/mcp.rs#L178-L201
- Introduced `McpEscalationPolicyFactory` that stores MCP-only state
(`RequestContext`, `preserve_program_paths`) and implements the new
trait.
-
https://github.com/openai/codex/blob/main/codex-rs/exec-server/src/posix/mcp.rs#L100-L117
- Updated `shell()` to pass a `McpEscalationPolicyFactory` instance into
`run_escalate_server`, so the server remains the MCP-specific wiring
layer.
-
https://github.com/openai/codex/blob/main/codex-rs/exec-server/src/posix/mcp.rs#L163-L170
## Verification
- Build and test execution was not re-run in this pass; changes are
limited to `mcp.rs` and preserve the existing escalation flow semantics
by only extracting policy construction behind a factory.
---
[//]: # (BEGIN SAPLING FOOTER)
Stack created with [Sapling](https://sapling-scm.com). Best reviewed
with [ReviewStack](https://reviewstack.dev/openai/codex/pull/12555).
* #12556
* __->__ #12555