CI: Build C# with SDK 2.
@@ -45,7 +45,7 @@ BUILD_CSHARP_JAVA() {
"FROM buildpack-deps:stretch
${SETUP_CMDS}
RUN apt-get install -y --no-install-recommends \
- mono-mcs nuget \
+ mono-mcs mono-reference-assemblies-2.0 nuget \
dub \
default-jdk maven" \
"wget ${JDK8_URL} -O /opt/jdk8.zip && mkdir /opt/java && \
