Use rls alpha-2 in Dockerfile.
@@ -13,7 +13,7 @@ RUN pacman -S --noconfirm rustup \
&& paccache -r -k0 \
&& rustup default nightly
-RUN git clone https://github.com/rust-lang-nursery/rls /opt/rls && cargo build --release --manifest-path=/opt/rls/Cargo.toml
+RUN git clone --branch alpha-2 --depth 1 https://github.com/rust-lang-nursery/rls /opt/rls && cargo build --release --manifest-path=/opt/rls/Cargo.toml
RUN timeout 5 cargo run --release --manifest-path=/opt/rls/Cargo.toml
