Steps: * Checkout commit b32e6e6ac8921035177256ab6806e6ab0d4b9b94 * Have `profile = "library"` in `config.toml`. In particular, this implies `download-ci-llvm = "if-available"` * Run `./x.py doc` Output (on the second run): ``` Updating only changed submodules Submodules updated in 0.06 seconds Finished dev [unoptimized + debuginfo] target(s) in 0.18s Generating unstable book md files (x86_64-unknown-linux-gnu) Building stage0 tool unstable-book-gen (x86_64-unknown-linux-gnu) Finished release [optimized] target(s) in 0.12s Building stage0 tool rustbook (x86_64-unknown-linux-gnu) Finished release [optimized] target(s) in 0.16s Rustbook (x86_64-unknown-linux-gnu) - unstable-book Documenting standalone (x86_64-unknown-linux-gnu) Documenting book redirect pages (x86_64-unknown-linux-gnu) Documenting stage0 std (x86_64-unknown-linux-gnu) Building stage0 std artifacts (x86_64-unknown-linux-gnu -> x86_64-unknown-linux-gnu) Finished release [optimized] target(s) in 0.19s Copying stage0 std from stage0 (x86_64-unknown-linux-gnu -> x86_64-unknown-linux-gnu / x86_64-unknown-linux-gnu) Finished release [optimized] target(s) in 0.24s Finished release [optimized] target(s) in 0.27s Finished release [optimized] target(s) in 0.21s Finished release [optimized] target(s) in 0.19s Finished release [optimized] target(s) in 0.20s Documenting stage0 compiler (x86_64-unknown-linux-gnu) skipping - compiler/librustdoc docs disabled Documenting stage0 rustdoc (x86_64-unknown-linux-gnu) skipping - compiler/librustdoc docs disabled Documenting error index (x86_64-unknown-linux-gnu) Building stage0 compiler artifacts (x86_64-unknown-linux-gnu -> x86_64-unknown-linux-gnu) Finished release [optimized] target(s) in 0.21s Copying stage0 rustc from stage0 (x86_64-unknown-linux-gnu -> x86_64-unknown-linux-gnu / x86_64-unknown-linux-gnu) Building stage0 tool error_index_generator (x86_64-unknown-linux-gnu) Finished release [optimized] target(s) in 0.16s /home/simon/projects/rust/build/x86_64-unknown-linux-gnu/stage0-tools-bin/error_index_generator: error while loading shared libraries: libLLVM-11-rust-1.50.0-nightly.so: cannot open shared object file: No such file or directory command did not execute successfully: "/home/simon/projects/rust/build/x86_64-unknown-linux-gnu/stage0-tools-bin/error_index_generator" "html" "/home/simon/projects/rust/build/x86_64-unknown-linux-gnu/doc/error-index.html" "1.50.0" expected success, got: exit code: 127 failed to run: /home/simon/projects/rust/build/bootstrap/debug/bootstrap doc ```