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## What changed This PR makes the default Cargo dev profile use line-tables-only debug info: ```toml [profile.dev] debug = 1 ``` That keeps useful backtraces while avoiding the cost of full variable debug info in normal local dev builds. This also makes the Bazel CI setting explicit with `-Cdebuginfo=0` for target and exec-configuration Rust actions. Bazel/rules_rust does not read Cargo profiles for this setting, and the current fastbuild action already emitted `--codegen=debuginfo=0`; the Bazel part of this PR makes that choice direct in our build configuration. ## Why The slow codex-core rebuilds are dominated by debug-info codegen, not parsing or type checking. On a warm-dependency package rebuild, the baseline codex-core compile was about 39.5s wall / 38.9s rustc total, with codegen_crate around 14.0s and LLVM_passes around 13.4s. Setting codex-core to line-tables-only debug info brought that to about 27.2s wall / 26.7s rustc total, with codegen_crate around 3.1s and LLVM_passes around 2.8s. `debug = 0` was only about another 0.7s faster than `debug = 1` in the codex-core measurement, so `debug = 1` is the better default dev tradeoff: it captures nearly all of the compile-time win while preserving basic debuggability. I also sampled other first-party crates instead of keeping a codex-core-only package override. codex-app-server showed the same pattern: rustc total dropped from 15.85s to 10.48s, while codegen_crate plus LLVM_passes dropped from about 13.47s to 3.23s. codex-app-server-protocol had a smaller but still real improvement, 16.05s to 14.58s total, and smaller crates showed modest wins. That points to a workspace dev-profile policy rather than a hand-maintained list of large crates. ## Relationship to #18612 [#18612](#18612) added the `dev-small` profile. That remains useful when someone wants a working local build quickly and is willing to opt in with `cargo build --profile dev-small`. This PR is deliberately less aggressive: it changes the common default dev profile while preserving line tables/backtraces. `dev-small` remains the explicit "build quickly, no debuggability concern" path. ## Other investigation I looked for another structural win comparable to [#16631](#16631) and [#16630](#16630), but did not find one. The attempted TOML monomorphization changes were noisy or worse in measurement, and the async task changes reduced some instantiations but only translated to roughly a one-second improvement while being much more disruptive. The debug-info setting was the one repeatable, material win that survived measurement. ## Verification - `just bazel-lock-update` - `just bazel-lock-check` - `cargo check -p codex-core --lib` - `cargo test -p codex-core --lib` - Bazel `aquery --config=ci-linux` confirmed `--codegen=debuginfo=0` and `-Cdebuginfo=0` for `//codex-rs/core:core` --- [//]: # (BEGIN SAPLING FOOTER) Stack created with [Sapling](https://sapling-scm.com). Best reviewed with [ReviewStack](https://reviewstack.dev/openai/codex/pull/18844). * #18846 * __->__ #18844
test-log is only used by codex-core tests, so it does not need to be part of the normal codex-core dependency graph. Keeping it in dev-dependencies removes it from normal builds and keeps the production dependency set a little smaller. Verification: - `cargo tree -p codex-core --edges normal --invert test-log` - `cargo check -p codex-core --lib` - `cargo test -p codex-core --lib`
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The
test-logcrate is only used bycodex-coretests, so it does not needto be part of the normal
codex-coredependency graph. Keepingtest-logindev-dependenciesremoves it from normalcodex-corebuilds and keeps theproduction dependency set a little smaller.
Verification:
cargo tree -p codex-core --edges normal --invert test-logcargo check -p codex-core --libcargo test -p codex-core --lib