bootstrap `core::builder::tests::dist::dist_only_cross_host` fails locally

[jieyouxu]

EDIT: I figured it out, it's because my local src/tools/cargo submodule was very corrupted, I had to rm -rf the submodule's .git folder and config and also remove a lock on .gitignore because yeah. Opening an issue in case someone else ever runs into this so it shows up in search results.

---

I'm on x86_64-unknown-linux-gnu (wsl), and this bootstrap unit tests seemingly failed locally (I am working on unrelated changes AFAIK):

---- core::builder::tests::dist::dist_only_cross_host stdout ----
thread 'core::builder::tests::dist::dist_only_cross_host' panicked at src/lib.rs:1567:20:
fs::read_to_string(toml_file_name) failed with No such file or directory (os error 2)
stack backtrace:
   0: rust_begin_unwind
             at /rustc/b4297a573b4eefacd62e7ea1ba071536282d3254/library/std/src/panicking.rs:665:5
   1: core::panicking::panic_fmt
             at /rustc/b4297a573b4eefacd62e7ea1ba071536282d3254/library/core/src/panicking.rs:76:14
   2: bootstrap::Build::release_num
             at ./src/utils/helpers.rs:37:23
   3: bootstrap::utils::tarball::OverlayKind::version
             at ./src/utils/tarball.rs:84:54
   4: bootstrap::utils::tarball::Tarball::run
             at ./src/utils/tarball.rs:316:65
   5: bootstrap::utils::tarball::Tarball::generate
             at ./src/utils/tarball.rs:244:9
   6: <bootstrap::core::build_steps::dist::Cargo as bootstrap::core::builder::Step>::run
             at ./src/core/build_steps/dist.rs:1120:14
   7: bootstrap::core::builder::Builder::ensure
             at ./src/core/builder/mod.rs:1455:23
   8: <bootstrap::core::build_steps::dist::Cargo as bootstrap::core::builder::Step>::make_run
             at ./src/core/build_steps/dist.rs:1092:9
   9: bootstrap::core::builder::StepDescription::maybe_run
             at ./src/core/builder/mod.rs:388:13
  10: bootstrap::core::builder::StepDescription::run
             at ./src/core/builder/mod.rs:438:21
  11: bootstrap::core::builder::Builder::run_step_descriptions
             at ./src/core/builder/mod.rs:1167:9
  12: bootstrap::core::builder::tests::run_build
             at ./src/core/builder/tests.rs:58:5
  13: bootstrap::core::builder::tests::dist::dist_only_cross_host
             at ./src/core/builder/tests.rs:444:25
  14: bootstrap::core::builder::tests::dist::dist_only_cross_host::{{closure}}
             at ./src/core/builder/tests.rs:437:30
  15: core::ops::function::FnOnce::call_once
             at /rustc/b4297a573b4eefacd62e7ea1ba071536282d3254/library/core/src/ops/function.rs:250:5
  16: core::ops::function::FnOnce::call_once
             at /rustc/b4297a573b4eefacd62e7ea1ba071536282d3254/library/core/src/ops/function.rs:250:5
note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.


failures:
    core::builder::tests::dist::dist_only_cross_host

[jieyouxu]

Documented in dev-guide via rust-lang/rustc-dev-guide#2152: https://rustc-dev-guide.rust-lang.org/git.html#overcoming-fatal-not-a-git-repository-submodulegitmodulessubmodule

Sometimes, for some forsaken reason, you might run into

fatal: not a git repository: src/gcc/../../.git/modules/src/gcc

In this situation, for the given submodule path, i.e. <submodule_path> = src/gcc in this example, you need to:

1. rm -rf <submodule_path>/.git
2. rm -rf .git/modules/<submodule_path>/config
3. rm -rf .gitconfig.lock if somehow the .gitconfig lock is orphaned.

Then do something like ./x fmt to have bootstrap manage the submodule checkouts for you.