Simplify c2rust (with latest C2Rust version)

.github/workflows/build.yml

@@ -129,6 +129,9 @@ jobs:
 
       - name: Rust build test
         run: |
+          # Some of the above are executed by root, creating ~/.cargo/git as
+          # that user, blocking downloads of own libraries.
+          rm -rf ~/.cargo
           # Once a release is out that can be built on stable, this switcharoo
           # can be removed -- until then, each release of RIOT is only
           # supported with the very Rust version that was the configured

riotbuild/Dockerfile

@@ -34,8 +34,6 @@ RUN mkdir /pkgs
 COPY files/libsocketcan-dev_0.0.11-1_i386.deb /pkgs/libsocketcan-dev_0.0.11-1_i386.deb
 COPY files/libsocketcan2_0.0.11-1_i386.deb /pkgs/libsocketcan2_0.0.11-1_i386.deb
 
-COPY --from=chrysn/c2rust-built:for-riot /c2rust.deb /pkgs
-
 # The following package groups will be installed:
 # - update the package index files to latest available version
 # - native platform development and build system functionality (about 400 MB installed)
@@ -107,6 +105,11 @@ RUN \
         llvm \
         clang \
         clang-tools \
+    && echo 'Installing C2Rust (build) dependencies' >&2 && \
+    apt-get -y --no-install-recommends install \
+        libclang-dev \
+        libssl-dev \
+        llvm-dev \
         && \
     SYMS=$(find /usr/bin -type l) && \
     for file in ${SYMS}; do \
@@ -309,6 +312,12 @@ RUN \
         true; \
     done"
 
+RUN \
+    echo 'Installing C2Rust' >&2 && \
+    CARGO_HOME=/opt/rustup/.cargo cargo install --no-track --locked c2rust --git https://github.com/immunant/c2rust --rev ed56c794230bbf5a0e417941e4778316d31ab114 && \
+    echo 'Cleaning up root-owned crates.io cache' >&2 && \
+    rm -rf /opt/rustup/.cargo/{git,registry,.package-cache}
+
 # get Dockerfile version from build args
 ARG RIOTBUILD_VERSION=unknown
 ENV RIOTBUILD_VERSION $RIOTBUILD_VERSION