diff --git a/.github/workflows/docker_linuxes.yml b/.github/workflows/docker_linuxes.yml
index 246927f..51abf6b 100644
--- a/.github/workflows/docker_linuxes.yml
+++ b/.github/workflows/docker_linuxes.yml
@@ -112,6 +112,18 @@ jobs:
     - name: Run unit tests (ctest) within the Docker image
       run: docker run ctl:latest sh -c "cd ./build && ctest"
 
+  ubuntu-latest-clang:
+
+    runs-on: ubuntu-latest
+    
+    steps:
+    - uses: actions/checkout@v4
+    - name: Build the Docker image
+      run: docker build --no-cache --rm -f ./docker/Dockerfile_ubuntu_latest_clang -t ctl:latest .
+    
+    - name: Run unit tests (ctest) within the Docker image
+      run: docker run ctl:latest sh -c "cd ./build && ctest"
+
   redhat-ubi8:
 
     runs-on: ubuntu-latest
@@ -223,4 +235,24 @@ jobs:
 
       - name: Run the docker that runs valgrind
         run: docker run ctl:latest 
-          
\ No newline at end of file
+
+  gentoo:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v4
+    - name: Build the Docker image
+      run: docker build --no-cache --rm -f ./docker/Dockerfile_gentoo -t ctl:latest .
+
+    - name: Run unit tests (ctest) within the Docker image
+      run: docker run ctl:latest sh -c "cd ./build && ctest"
+
+  gentoo-clang:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v4
+    - name: Build the Docker image
+      run: docker build --no-cache --rm -f ./docker/Dockerfile_gentoo_clang -t ctl:latest .
+
+    - name: Run unit tests (ctest) within the Docker image
+      run: docker run ctl:latest sh -c "cd ./build && ctest"
+
diff --git a/.github/workflows/ubuntu_arm_release.yml b/.github/workflows/ubuntu_arm_release.yml
index 321b61f..73c82f1 100644
--- a/.github/workflows/ubuntu_arm_release.yml
+++ b/.github/workflows/ubuntu_arm_release.yml
@@ -27,6 +27,9 @@ jobs:
 
     steps:
 
+    - name: run apt-get update
+      run: sudo apt-get -y update
+
     - name: install libtiff
       run: sudo apt-get -y install libtiff-dev
 
diff --git a/docker/Dockerfile_gentoo b/docker/Dockerfile_gentoo
new file mode 100644
index 0000000..8b74394
--- /dev/null
+++ b/docker/Dockerfile_gentoo
@@ -0,0 +1,25 @@
+FROM gentoo/stage3
+
+# update packages
+RUN emaint --auto sync
+
+# install development tools
+RUN emerge cmake
+
+# install CTL required dependencies
+RUN emerge openexr
+
+# install CTL optional dependencies
+RUN emerge tiff
+
+# build CTL
+WORKDIR /usr/src/CTL
+COPY . .
+WORKDIR /usr/src/CTL/build
+RUN rm -R * || true
+RUN cmake ..
+RUN make
+RUN make install
+
+# finalize docker environment
+WORKDIR /usr/src/CTL
diff --git a/docker/Dockerfile_gentoo_clang b/docker/Dockerfile_gentoo_clang
new file mode 100644
index 0000000..660e7c6
--- /dev/null
+++ b/docker/Dockerfile_gentoo_clang
@@ -0,0 +1,44 @@
+FROM gentoo/stage3
+
+# update packages
+RUN emaint --auto sync
+
+# install development tools
+RUN emerge cmake
+RUN emerge llvm-core/clang
+
+# install CTL required dependencies
+RUN emerge openexr
+
+# install CTL optional dependencies
+RUN emerge tiff
+
+# switch to clang system wide
+# based on https://wiki.gentoo.org/wiki/LLVM/Clang
+# RUN printf "CC=clang\n" >> /etc/portage/make.conf
+# RUN printf "CPP=clang-cpp\n" >> /etc/portage/make.conf
+# RUN printf "CXX=clang++\n" >> /etc/portage/make.conf
+# RUN printf "AR=llvm-ar\n" >> /etc/portage/make.conf
+# RUN printf "NM=llvm-nm\n" >> /etc/portage/make.conf
+# RUN printf "RANLIB=llvm-ranlib\n" >> /etc/portage/make.conf
+
+# switch to the make.profile symlink
+#RUN eselect profile set 39
+
+# update path
+# RUN env-update && . /etc/profile
+#RUN source /etc/profile && env-update
+#RUN source /etc/profile
+ENV PATH=$PATH:/usr/lib/llvm/19/bin
+
+# build CTL
+WORKDIR /usr/src/CTL
+COPY . .
+WORKDIR /usr/src/CTL/build
+RUN rm -R * || true
+RUN cmake .. -DCMAKE_CXX_COMPILER=clang++
+RUN make
+RUN make install
+
+# finalize docker environment
+WORKDIR /usr/src/CTL
diff --git a/docker/Dockerfile_ubuntu_latest_clang b/docker/Dockerfile_ubuntu_latest_clang
new file mode 100644
index 0000000..5645c6d
--- /dev/null
+++ b/docker/Dockerfile_ubuntu_latest_clang
@@ -0,0 +1,27 @@
+FROM ubuntu:latest
+
+RUN apt-get update
+
+# disable interactive install 
+ENV DEBIAN_FRONTEND noninteractive
+
+# install developement tools
+RUN apt-get -y install cmake
+RUN apt-get -y install clang
+
+# install CTL dependencies
+RUN apt-get -y install libopenexr-dev
+RUN apt-get -y install libtiff-dev
+
+# build CTL
+WORKDIR /usr/src/CTL
+COPY . .
+WORKDIR /usr/src/CTL/build
+RUN rm -R * || true
+RUN cmake ..
+RUN make
+RUN make install
+
+# finalize docker environment
+WORKDIR /usr/src/CTL
+