diff --git a/containers/jug/dev.Dockerfile b/containers/jug/dev.Dockerfile
index ee6c6e02c74813e4d5db4b8026cd37d2a8f949d1..76cd6b0651215f67a4505fcad01efc7ae5c1f9a7 100644
--- a/containers/jug/dev.Dockerfile
+++ b/containers/jug/dev.Dockerfile
@@ -157,11 +157,11 @@ make --jobs ${jobs} --keep-going --directory /opt/spack-environment \
   SPACK_ENV=${SPACK_ENV} \
   BUILDCACHE_OCI_PROMPT="eicweb" \
   BUILDCACHE_OCI_FINAL="ghcr"
-spack find --implicit --no-groups \
+spack find --long --no-groups \
 | sed -e '1,/Installed packages/d;s/\([^@]*\).*/\1/g' \
-| uniq -d | grep -v py-pip | grep -v py-cython \
+| uniq -D -f1 | grep -v -w epic \
 | tee /tmp/duplicates.txt
-test -s /tmp/duplicates.txt && exit 1
+test -s /tmp/duplicates.txt && ( cat /tmp/duplicates.txt | while read hash spec ; do spack spec /${hash} ; done ) && exit 1
 ccache --show-stats
 ccache --zero-stats
 EOF