diff --git a/containers/builder/Dockerfile b/containers/builder/Dockerfile
index 5c1f58d3373cfa687410502273cb910c6c6d1baf..b4ad45046c3d881c20dbc92707647884ec39e5e7 100644
--- a/containers/builder/Dockerfile
+++ b/containers/builder/Dockerfile
@@ -19,11 +19,11 @@ ENV DOCKERFILE_BASE=debian            \
 
 
 ## install ghostview/ghostscript needed by some of the tools
-RUN apt-get -yqq update \
- && apt-get -yqq install --no-install-recommends \
-        ghostscript \
-        gv \
- && rm -rf /var/lib/apt/lists/*
+#RUN apt-get -yqq update \
+# && apt-get -yqq install --no-install-recommends \
+#        ghostscript \
+#        gv \
+# && rm -rf /var/lib/apt/lists/*
 
 ## Setup our environment definition
 COPY spack.yaml /opt/spack-environment/spack.yaml
@@ -37,6 +37,12 @@ RUN rm -rf $SPACK_ROOT/np-spack \
  && echo " - $SPACK_ROOT/np-spack" >> $SPACK_ROOT/etc/spack/repos.yaml
 COPY np-spack $SPACK_ROOT/np-spack
 
+## FIXME: need to use local filesystem for spack buildcache upstream
+RUN ls /spack-mirror \
+ && spack mirror remove silicon \
+ && spack mirror add local /spack-mirror \
+ && spack mirror list
+
 ## Install the software, no garbage collection at this stage
 ## as this is a raw builder image
 RUN cd /opt/spack-environment \
@@ -44,27 +50,32 @@ RUN cd /opt/spack-environment \
  && spack install -j64 \
  && spack clean -a
 
-## Install additional python packages
-RUN cd /opt/spack-environment && spack env activate . \
- && pip install --trusted-host pypi.org \
-                --trusted-host files.pythonhosted.org \
-                --no-cache-dir \
-        ipython matplotlib scipy yapf
-
-# Modifications to the environment that are necessary to run
-# Also make sure we keep the /lib/x86_65-linux-gnu in our PATH
+## extra post-spack steps
+## Including some small fixes:
+##   - Somehow PODIO env isn't automatically set, 
+##   - and Gaudi likes BINARY_TAG to be set
 RUN cd /opt/spack-environment \
+ && echo -n ""                                        \
+ && echo "Grabbing environment info"                  \
  && spack env activate --sh -d . > /etc/profile.d/z10_spack_environment.sh \
- && sed -i "s?LD_LIBRARY_PATH=?&/lib/x86_64-linux-gnu:?" /etc/profile.d/z10_spack_environment.sh
-
-# Add some extra environment variables
-# Somehow PODIO env isn't automatically set, 
-# and Gaudi likes BINARY_TAG to be set
-RUN cd /opt/spack-environment \
- && spack env activate . \
+ && sed -i "s?LD_LIBRARY_PATH=?&/lib/x86_64-linux-gnu:?" /etc/profile.d/z10_spack_environment.sh \
+ && cd /opt/spack-environment                         \
+ && echo -n ""                                        \
+ && echo "Add extra environment variables for Podio and Gaudi" \
+ && spack env activate .                              \
  && export PODIO=`spack find -p podio | grep software | awk '{print $2}'` \
  && echo "export PODIO=${PODIO};" >> /etc/profile.d/z10_spack_environment.sh \
- && echo "export BINARY_TAG=x86_64-linux-gcc9-opt" >> /etc/profile.d/z10_spack_environment.sh
+ && echo "export BINARY_TAG=x86_64-linux-gcc9-opt" >> /etc/profile.d/z10_spack_environment.sh \
+ && cd /opt/spack-environment && spack env activate . \
+ && echo -n ""                                        \
+ && echo "Installing additional python packages"      \
+ && pip install --trusted-host pypi.org               \
+                --trusted-host files.pythonhosted.org \
+                --no-cache-dir                        \
+        ipython matplotlib scipy yapf                 \
+ && echo -n ""                                        \
+ && echo "Executing cmake patch for dd4hep 16.1"      \ 
+ && sed -i "s/FIND_PACKAGE(Python/#&/" /usr/local/cmake/DD4hepBuild.cmake
 
 ## make sure we have the entrypoints setup correctly
 ENTRYPOINT []