Use cargo install rather than cargo build
The problem fixed in commit ("cargo install says tiny-keccak needs
the feature set") was detected by cargo install, not cargo build. So, try
to use cargo install during CI testing/building.
@@ -12,10 +12,9 @@ COPY . src
WORKDIR /src/stdlib/
RUN clang-10 --target=wasm32 -c -emit-llvm -O3 -ffreestanding -fno-builtin -Wall stdlib.c sha3.c substrate.c ripemd160.c
-WORKDIR /src/
-RUN cargo build --release
+RUN cargo install --path /src
FROM ubuntu:20.04
-COPY --from=builder /src/target/release/solang /usr/bin/solang
+COPY --from=builder /root/.cargo/bin/solang /usr/bin/solang
ENTRYPOINT ["/usr/bin/solang"]
