install only the required components of the toolchain

- do'not install libpthread, libomp, newlib

Dockerfile

@@ -16,18 +16,16 @@ RUN echo "deb [trusted=yes] https://dl.bintray.com/hermitcore/ubuntu bionic main
 RUN apt-get -qq update
 
 # Install required packets from ubuntu repository
-RUN apt-get install -y --allow-unauthenticated binutils-hermit newlib-hermit-rs pte-hermit-rs gcc-hermit-rs libhermit-rs
+RUN apt-get install -y --allow-unauthenticated binutils-hermit gcc-hermit-rs #newlib-hermit-rs pte-hermit-rs gcc-hermit-rs libhermit-rs
 
 # Install Rust toolchain
 RUN cp /src/config.toml /src/rust
 RUN cd /src/rust && ./x.py install
-#RUN PATH="/opt/hermit/bin:/root/.cargo/bin:${PATH}" /root/.cargo/bin/cargo install cargo-xbuild
-#RUN PATH="/opt/hermit/bin:/root/.cargo/bin:${PATH}" /root/.cargo/bin/cargo install --git https://github.com/hermitcore/objmv.git
-#RUN PATH="/opt/hermit/bin:/root/.cargo/bin:${PATH}" /root/.cargo/bin/cargo install --git https://github.com/hermitcore/pci_ids_parser.git
 
 # Clean up
 RUN apt-get autoremove -y && apt-get clean -y && rm -rf /var/lib/apt/lists/*
 RUN rm -rf /src
 
 ENV PATH="/opt/hermit/bin:/root/.cargo/bin:${PATH}"
+ENV XARGO_RUST_SRC="/root/.cargo/lib/rustlib/src/rust/src/"
 ENV EDITOR=vim