diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 8652caf897..0d49b826dd 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -502,7 +502,7 @@ jobs:
             # Ensure we are testing all the deps we think we are. We would
             # like this test to have minimal missing dependencies.
             required_deps: all
-            optional_deps: 'CUDAToolkit;DCMTK;JXL;Nuke;OpenCV;OpenGL;OpenVDB;R3DSDK'
+            optional_deps: 'CUDAToolkit;DCMTK;JXL;libuhdr;Nuke;OpenCV;OpenGL;openjph;R3DSDK;'
           - desc: all local builds gcc12 C++17 avx2 exr3.2 ocio2.3
             nametag: linux-local-builds
             runner: ubuntu-22.04
@@ -517,18 +517,19 @@ jobs:
                             PTEX_VERSION=v2.4.2
                             PUGIXML_VERSION=v1.14
                             WEBP_VERSION=v1.4.0
-          - desc: clang15 C++17 avx2 exr3.1 ocio2.3
-            nametag: linux-clang15
-            runner: ubuntu-22.04
-            cxx_compiler: clang++-15
-            cc_compiler: clang-15
+          - desc: clang18 C++17 avx2 exr3.1 ocio2.3
+            nametag: linux-clang18
+            runner: ubuntu-24.04
+            cxx_compiler: clang++
+            cc_compiler: clang
             cxx_std: 17
             fmt_ver: 10.1.1
             opencolorio_ver: v2.3.0
             openexr_ver: v3.1.13
             pybind11_ver: v2.12.0
-            python_ver: "3.10"
+            python_ver: "3.12"
             simd: avx2,f16c
+            setenvs: export USE_OPENVDB=0
           - desc: Linux ARM latest releases gcc14 C++20 py3.12 exr3.4 ocio2.4
             nametag: linux-arm-latest-releases
             runner: ubuntu-24.04-arm
diff --git a/src/build-scripts/gh-installdeps.bash b/src/build-scripts/gh-installdeps.bash
index fb1d2b8213..0dabcf61e0 100755
--- a/src/build-scripts/gh-installdeps.bash
+++ b/src/build-scripts/gh-installdeps.bash
@@ -96,14 +96,17 @@ else
     if [[ "${SKIP_SYSTEM_DEPS_INSTALL}" != "1" ]] ; then
         time sudo apt-get -q install -y --fix-missing \
             git cmake ninja-build ccache g++ \
-            libilmbase-dev libopenexr-dev \
-            libtiff-dev libgif-dev libpng-dev \
+            libtiff-dev libgif-dev libpng-dev libjpeg-dev \
             libraw-dev libwebp-dev \
             libavcodec-dev libavformat-dev libswscale-dev libavutil-dev \
             dcmtk libopenvdb-dev \
             libfreetype6-dev \
             libopencolorio-dev \
-            libtbb-dev || true
+            libtbb-dev \
+            libdeflate-dev bzip2
+        # Iffy ones get the "|| true" treatment so failure is ok
+        time sudo apt-get -q install -y --fix-missing \
+            libjxl-dev || true
     fi
     if [[ "${USE_OPENCV}" != "0" ]] && [[ "${INSTALL_OPENCV}" != "0" ]] ; then
         sudo apt-get -q install -y --fix-missing libopencv-dev || true
@@ -133,6 +136,10 @@ else
             libheif-plugin-x265 libheif-dev || true
     fi
 
+    if [[ "${USE_FFMPEG}" != "0" ]] ; then
+        time sudo apt-get -q install -y ffmpeg || true
+    fi
+
     export CMAKE_PREFIX_PATH=/usr/lib/x86_64-linux-gnu:$CMAKE_PREFIX_PATH
 
     if [[ "$CXX" == "icpc" || "$CC" == "icc" || "$USE_ICC" != "" || "$USE_ICX" != "" ]] ; then