No matching toolchain when trying to run rust_analyzer

I have `rust_register_toolchains()` in my `WORKSPACE`, and I've also tried `register_toolchains(rust_analyzer_toolchain_repository())`, but trying to run `rust_analyzer` like

```sh
bazel run @rules_rust//tools/rust_analyzer:gen_rust_project
```

gives this error

```
ERROR: Analysis of aspects '[@rules_rust//rust:defs.bzl%rust_analyzer_aspect] with parameters {} on //target' failed; build aborted: No matching toolchains found for types @rules_rust//rust:toolchain_type.
To debug, rerun with --toolchain_resolution_debug='@rules_rust//rust:toolchain_type'
```

Running with the suggested debug argument, it looks like a toolchain is indeed identified (I've removed rejected toolchains from the output):

```
INFO: ToolchainResolution: Target platform //linux_x86: Selected execution platform //linux_x86, type @bazel_tools//tools/cpp:toolchain_type -> toolchain @llvm_toolchain//:cc-clang-x86_64-linux, type @rules_rust//rust:toolchain_type -> toolchain @rust_linux_x86_64__x86_64-unknown-linux-gnu__stable_tools//:rust_toolchain
INFO: ToolchainResolution: Target platform //linux_x86: Selected execution platform //linux_x86, type @rules_rust//rust/rust_analyzer:toolchain_type -> toolchain @rust_analyzer_1.72.0_tools//:rust_analyzer_toolchain, type @rules_rust//rust:toolchain_type -> toolchain @rust_linux_x86_64__x86_64-unknown-linux-gnu__stable_tools//:rust_toolchain
INFO: ToolchainResolution: Target platform //linux_x86: Selected execution platform //linux_x86, type @bazel_tools//tools/cpp:toolchain_type -> toolchain @llvm_toolchain//:cc-clang-x86_64-linux, type @rules_rust//rust:toolchain_type -> toolchain @rust_linux_x86_64__x86_64-unknown-linux-gnu__stable_tools//:rust_toolchain
```

It would seem to me that the first INFO line here shows bazel does find a toolchain for the given type. Why doesn't `rust_analyzer_aspect` find this? Should I be concerned about some duplicate information being shown in this debug output?