Auto merge of #135286 - matthiaskrgr:rollup-sxuq1nh, r=matthiaskrgr

Rollup of 3 pull requests

Successful merges:

 - #134898 (Make it easier to run CI jobs locally)
 - #135195 (Make `lit_to_mir_constant` and `lit_to_const` infallible)
 - #135261 (Account for identity substituted items in symbol mangling)

r? `@ghost`
`@rustbot` modify labels: rollup

src/building/optimized-build.md

@@ -126,4 +126,4 @@ Here is an example of how can `opt-dist` be used locally (outside of CI):
 [`Environment`]: https://github.com/rust-lang/rust/blob/ee451f8faccf3050c76cdcd82543c917b40c7962/src/tools/opt-dist/src/environment.rs#L5
 
 > Note: if you want to run the actual CI pipeline, instead of running `opt-dist` locally,
-> you can execute `DEPLOY=1 src/ci/docker/run.sh dist-x86_64-linux`.
+> you can execute `python3 src/ci/github-actions/ci.py run-local dist-x86_64-linux`.

src/tests/ci.md

@@ -28,7 +28,7 @@ Our CI is primarily executed on [GitHub Actions], with a single workflow defined
 in [`.github/workflows/ci.yml`], which contains a bunch of steps that are
 unified for all CI jobs that we execute. When a commit is pushed to a
 corresponding branch or a PR, the workflow executes the
-[`calculate-job-matrix.py`] script, which dynamically generates the specific CI
+[`ci.py`] script, which dynamically generates the specific CI
 jobs that should be executed. This script uses the [`jobs.yml`] file as an
 input, which contains a declarative configuration of all our CI jobs.
 
@@ -299,8 +299,7 @@ platform’s custom [Docker container]. This has a lot of advantages for us:
 - We can avoid reinstalling tools (like QEMU or the Android emulator) every time
   thanks to Docker image caching.
 - Users can run the same tests in the same environment locally by just running
-  `src/ci/docker/run.sh image-name`, which is awesome to debug failures. Note
+  `python3 src/ci/github-actions/ci.py run-local <job-name>`, which is awesome to debug failures. Note that there are only linux docker images available locally due to licensing and
-  that there are only linux docker images available locally due to licensing and
   other restrictions.
 
 The docker images prefixed with `dist-` are used for building artifacts while
@@ -413,7 +412,7 @@ To learn more about the dashboard, see the [Datadog CI docs].
 [GitHub Actions]: https://github.com/rust-lang/rust/actions
 [`jobs.yml`]: https://github.com/rust-lang/rust/blob/master/src/ci/github-actions/jobs.yml
 [`.github/workflows/ci.yml`]: https://github.com/rust-lang/rust/blob/master/.github/workflows/ci.yml
-[`calculate-job-matrix.py`]: https://github.com/rust-lang/rust/blob/master/src/ci/github-actions/calculate-job-matrix.py
+[`ci.py`]: https://github.com/rust-lang/rust/blob/master/src/ci/github-actions/ci.py
 [rust-lang-ci]: https://github.com/rust-lang-ci/rust/actions
 [bors]: https://github.com/bors
 [homu]: https://github.com/rust-lang/homu

src/tests/docker.md

@@ -45,6 +45,15 @@ Some additional notes about using the Docker images:
   containers. With the container name, run `docker exec -it <CONTAINER>
   /bin/bash` where `<CONTAINER>` is the container name like `4ba195e95cef`.
 
+The approach described above is a relatively low-level interface for running the Docker images
+directly. If you want to run a full CI Linux job locally with Docker, in a way that is as close to CI as possible, you can use the following command:
+
+```bash
+python3 src/ci/github-actions/ci.py run-local <job-name>
+# For example:
+python3 src/ci/github-actions/ci.py run-local dist-x86_64-linux-alt
+```
+
 [Docker]: https://www.docker.com/
 [`src/ci/docker`]: https://github.com/rust-lang/rust/tree/master/src/ci/docker
 [`src/ci/docker/run.sh`]: https://github.com/rust-lang/rust/blob/master/src/ci/docker/run.sh