diff --git a/build/docker/ubuntu-xenial/Dockerfile b/build/docker/ubuntu-xenial/Dockerfile
index 119d4cd..8dc6497 100644
--- a/build/docker/ubuntu-xenial/Dockerfile
+++ b/build/docker/ubuntu-xenial/Dockerfile
@@ -14,7 +14,7 @@
 # Apache Thrift Docker build environment for Ubuntu Xenial
 # Using all stock Ubuntu Xenial packaging except for:
 # - d: does not come with Ubuntu so we're installing 2.075.1 for coverage
-# - dart: does not come with Ubuntu so we're installing 1.24.3 for coverage
+# - dart: does not come with Ubuntu so we're installing 2.0.0-1 for coverage
 # - dotnet: does not come with Ubuntu
 # - go: Xenial comes with 1.6, but we need 1.10 or later
 # - nodejs: Xenial comes with 4.2.6 which exits LTS April 2018, so we're installing 6.x
@@ -35,29 +35,29 @@
       apt-utils \
       curl \
       software-properties-common \
-      wget
+      wget && \
 
 # csharp (mono)
-# RUN echo "deb http://download.mono-project.com/repo/debian xenial main" | tee /etc/apt/sources.list.d/mono.list && \
-#     apt-key adv --keyserver keyserver.ubuntu.com --recv-keys A6A19B38D3D831EF
+# echo "deb http://download.mono-project.com/repo/debian xenial main" | tee /etc/apt/sources.list.d/mono.list && \
+#     apt-key adv --keyserver keyserver.ubuntu.com --recv-keys A6A19B38D3D831EF && \
 
 # D
-RUN apt-key adv --keyserver keyserver.ubuntu.com --recv-keys EBCF975E5BA24D5E && \
+    apt-key adv --keyserver keyserver.ubuntu.com --recv-keys EBCF975E5BA24D5E && \
     wget http://master.dl.sourceforge.net/project/d-apt/files/d-apt.list -O /etc/apt/sources.list.d/d-apt.list && \
-    wget -qO - https://dlang.org/d-keyring.gpg | apt-key add -
+    wget -qO - https://dlang.org/d-keyring.gpg | apt-key add - && \
 
 # Dart
-RUN curl https://dl-ssl.google.com/linux/linux_signing_key.pub | apt-key add - && \
+    curl https://dl-ssl.google.com/linux/linux_signing_key.pub | apt-key add - && \
     curl https://storage.googleapis.com/download.dartlang.org/linux/debian/dart_stable.list > \
-      /etc/apt/sources.list.d/dart_stable.list
+      /etc/apt/sources.list.d/dart_stable.list && \
 
 # dotnet (core)
-RUN curl https://packages.microsoft.com/keys/microsoft.asc | gpg --dearmor > /etc/apt/trusted.gpg.d/microsoft.gpg && \
+    curl https://packages.microsoft.com/keys/microsoft.asc | gpg --dearmor > /etc/apt/trusted.gpg.d/microsoft.gpg && \
     echo "deb [arch=amd64] https://packages.microsoft.com/repos/microsoft-ubuntu-xenial-prod xenial main" > \
-      /etc/apt/sources.list.d/dotnetdev.list
+      /etc/apt/sources.list.d/dotnetdev.list && \
 
 # node.js
-RUN curl -sL https://deb.nodesource.com/gpgkey/nodesource.gpg.key | apt-key add - && \
+    curl -sL https://deb.nodesource.com/gpgkey/nodesource.gpg.key | apt-key add - && \
     echo "deb https://deb.nodesource.com/node_6.x xenial main" | tee /etc/apt/sources.list.d/nodesource.list
 
 ### install general dependencies
@@ -119,7 +119,7 @@
     mv openssl-1.1.6-1.0.1g/C/* /usr/include/dmd/druntime/import/C/ && \
     rm -rf openssl-1.1.6-1.0.1g
 
-ENV DART_VERSION 1.24.3-1
+ENV DART_VERSION 2.0.0-1
 RUN apt-get install -y --no-install-recommends \
 `# Dart dependencies` \
       dart=$DART_VERSION
@@ -151,7 +151,7 @@
       ln -s /usr/local/go/bin/go /usr/local/bin && \
       rm golang.tar.gz
 
-# due to a bug in cabal in xenial (cabal-install package) we pull in another:
+# cabal 1.22 in xenial is too old so we grab a pre-built 1.24 binary
 RUN apt-get install -y --no-install-recommends \
 `# Haskell dependencies` \
       ghc && \
@@ -160,7 +160,8 @@
     tar xzf cabal-install-1.24.0.2-x86_64-unknown-linux.tar.gz && \
     find dist-newstyle/ -type f -name cabal -exec mv {} /usr/bin \; && \
     rm -rf /tmp/cabal* && \
-    cabal --version
+    cabal --version && \
+    cabal update
 
 RUN apt-get install -y --no-install-recommends \
 `# Haxe dependencies` \
@@ -179,10 +180,11 @@
       openjdk-8-jdk \
       maven
 
-RUN apt-get install -y --no-install-recommends \
-`# Lua dependencies` \
-      lua5.2 \
-      lua5.2-dev
+# disabled: same as ubuntu-bionic jobs
+# RUN apt-get install -y --no-install-recommends \
+# `# Lua dependencies` \
+#       lua5.2 \
+#       lua5.2-dev
 # https://bugs.launchpad.net/ubuntu/+source/lua5.3/+bug/1707212
 # lua5.3 does not install alternatives so stick with 5.2 here
 
@@ -255,7 +257,7 @@
       ruby-bundler
 
 # Rust dependencies
-RUN curl https://sh.rustup.rs -sSf | sh -s -- --default-toolchain 1.35.0 -y
+RUN curl https://sh.rustup.rs -sSf | sh -s -- --default-toolchain 1.34.0 -y
 
 # Clean up
 RUN rm -rf /var/cache/apt/* && \