the download-ci-llvm experiment turned out to be too unreliable

Author: ZuseZ4

src/autodiff/installation.md

@@ -4,11 +4,11 @@ In the near future, `std::autodiff` should become available in nightly builds fo
 
 ## Build instructions
 
-First you need to clone and configure the Rust repository:
+First you need to clone and configure the Rust repository. Based on your preferences, you might also want to `--enable-clang` or `--enable-lld`.
 ```bash
 git clone [email protected]:rust-lang/rust
 cd rust
-./configure --release-channel=nightly --enable-llvm-enzyme --enable-llvm-assertions --enable-option-checking --disable-docs --set llvm.download-ci-llvm=true
+./configure --release-channel=nightly --enable-llvm-enzyme --enable-llvm-link-shared --enable-llvm-assertions --enable-ninja --enable-option-checking --disable-docs --set llvm.download-ci-llvm=false
 ```
 
 Afterwards you can build rustc using:
@@ -47,7 +47,7 @@ Then build rustc in a slightly altered way:
 ```bash
 git clone https://github.com/rust-lang/rust
 cd rust
-./configure --release-channel=nightly --enable-llvm-enzyme --enable-llvm-assertions --enable-option-checking --disable-docs --set llvm.download-ci-llvm=true
+./configure --release-channel=nightly --enable-llvm-enzyme --enable-llvm-link-shared --enable-llvm-assertions --enable-ninja --enable-option-checking --disable-docs --set llvm.download-ci-llvm=false
 ./x dist
 ```
 We then copy the tarball to our host. The dockerid is the newest entry under `docker ps -a`.