Auto merge of #39728 - eddyb:vendeur-tres-bien, r=alexcrichton

Automate vendoring by invoking cargo-vendor when building src dist tarballs.

This avoids #39633 bringing the `src/vendor` checked into git by #37524, past 200,000 lines of code.

I believe the strategy of having rustbuild run `cargo vendor` during the `dist src` step is sound.

However, the only way to be sure `cargo-vendor` exists is to run `cargo install --force cargo-vendor`, which will recompile it every time (not passing `--force` means you can't tell between "already exists" and "build error"). ~~This is quite suboptimal and I'd like to somehow do it in each `Dockerfile` that would need it.~~

* [ ] Cache `CARGO_HOME` (i.e. `~/.cargo`) between CI runs
  * `bin/cargo-vendor` and the actual caches are the relevant bits
* [x] Do not build `cargo-vendor` all the time
  * ~~Maybe detect `~/.cargo/bin/cargo-vendor` already exists?~~
  * ~~Could also try to build it in a `Dockerfile` but do we have `cargo`/`rustc` there?~~
  * Final solution: check `cargo install --list` for a line starting with `cargo-vendor `

cc @rust-lang/tools

1 files changed, 1 insertions, 0 deletions

diff --git a/configure b/configure
index d529375277b..372ee756534 100755
--- a/configure
+++ b/configure
@@ -647,6 +647,7 @@ opt llvm-version-check 1 "check if the LLVM version is supported, build anyway"
 opt codegen-tests 1 "run the src/test/codegen tests"
 opt option-checking 1 "complain about unrecognized options in this configure script"
 opt ninja 0 "build LLVM using the Ninja generator (for MSVC, requires building in the correct environment)"
+opt locked-deps 0 "force Cargo.lock to be up to date"
 opt vendor 0 "enable usage of vendored Rust crates"
 opt sanitizers 0 "build the sanitizer runtimes (asan, lsan, msan, tsan)"