Is installing from `cargo` supported?

Ran `CARGO_TARGET_DIR=/tmp/cargo-installVmzaQz cargo install --git https://github.com/awslabs/llrt`, got:
```
Compiling llrt_core v0.5.1-beta (/home/cc/.cargo/git/checkouts/llrt-0a7fdb298878dfd0/b4735e0/llrt_core)
error: failed to run custom build command for `llrt_core v0.5.1-beta (/home/cc/.cargo/git/checkouts/llrt-0a7fdb298878dfd0/b4735e0/llrt_core)`

Caused by:
process didn't exit successfully: `/tmp/cargo-installVmzaQz/release/build/llrt_core-273a7128c114ac0f/build-script-build` (exit status: 1)
--- stdout
cargo::rustc-check-cfg=cfg(rust_nightly)
cargo:rustc-cfg=rust_nightly
cargo:rerun-if-changed=../bundle/js
cargo:rerun-if-changed=Cargo.toml
cargo:rerun-if-changed=patches
cargo:info=
===============================
Uncompressed bytecode size: 0.000 B
===============================
cargo:info=Generating compression dictionary...

--- stderr
! Warning : nb of samples too low for proper processing !
! Please provide _one file per sample_.
! Alternatively, split files into fixed-size blocks representative of samples, with -B#
Error 14 : nb of samples too low
Error: Custom { kind: Other, error: "Failed to generate compression dictionary" }
warning: build failed, waiting for other jobs to finish...
error: failed to compile `llrt v0.5.1-beta (https://github.com/awslabs/llrt#b4735e08)`, intermediate artifacts can be found at `/tmp/cargo-installVmzaQz`.
To reuse those artifacts with a future compilation, set the environment variable `CARGO_TARGET_DIR` to that path.
```

Start by reproducing the reported `cargo install --git https://github.com/awslabs/llrt` command with the shown `CARGO_TARGET_DIR` setting and review the `llrt_core` build output. Trace the custom build step that generates the compression dictionary and determine whether Cargo installation is supported. Done means the command succeeds or the supported installation status and required alternative are clearly documented.

Written by the indexing model from the issue text.