diff --git a/.github/workflows/build-ruby.yml b/.github/workflows/build-ruby.yml
index 30f7c4d..07d8bab 100644
--- a/.github/workflows/build-ruby.yml
+++ b/.github/workflows/build-ruby.yml
@@ -185,6 +185,14 @@ jobs:
           docker run --platform linux/x86_64 --rm ${{ steps.vars.outputs.IMAGE }}:${{ steps.vars.outputs.TAG }} bundle --version
           docker run --platform linux/x86_64 --rm -v "${PWD}":"${PWD}" -w "${PWD}" -e BUNDLE_GEMFILE=gemfiles/${{ matrix.engine }}-${{ matrix.version }}.gemfile ${{ steps.vars.outputs.IMAGE }}:${{ steps.vars.outputs.TAG }} /bin/sh -c 'bundle install --with="test" --without="check ide" && bundle exec rake test'
 
+      # TODO: hardcoded musl, unify gnu instead
+      # TODO: hardcoded tags, use proper tag building
+      - name: Build single-arch compiler image (x86_64)
+        if: ${{ contains(matrix.arch, 'x86_64') && matrix.libc == 'musl' }}
+        run: |
+          docker buildx build ${{ steps.vars.outputs.SRC }} --builder=container --cache-from=type=registry,ref=${{ steps.vars.outputs.IMAGE }}:${{ steps.vars.outputs.RELEASE_TAG }}-gcc --output=type=image,push=false --platform linux/x86_64 -f ${{ steps.vars.outputs.DOCKERFILE }}.gcc
+      # TODO: add CI tag and test
+
       # Then, build image for aarch64 which, being emulated under qemu, is slower
       #
       # Tagging is necessary to reference the image for the testing step
@@ -211,6 +219,14 @@ jobs:
           docker run --platform linux/aarch64 --rm ${{ steps.vars.outputs.IMAGE }}:${{ steps.vars.outputs.TAG }} bundle --version
           docker run --platform linux/aarch64 --rm -v "${PWD}":"${PWD}" -w "${PWD}" -e BUNDLE_GEMFILE=gemfiles/${{ matrix.engine }}-${{ matrix.version }}.gemfile ${{ steps.vars.outputs.IMAGE }}:${{ steps.vars.outputs.TAG }} /bin/sh -c 'bundle install --with="test" --without="check ide" && bundle exec rake test'
 
+      # TODO: hardcoded musl, unify gnu instead
+      # TODO: hardcoded tags, use proper tag building
+      - name: Build single-arch compiler image (aarch64)
+        if: ${{ contains(matrix.arch, 'aarch64') && matrix.libc == 'musl' }}
+        run: |
+          docker buildx build ${{ steps.vars.outputs.SRC }} --builder=container --cache-from=type=registry,ref=${{ steps.vars.outputs.IMAGE }}:${{ steps.vars.outputs.RELEASE_TAG }}-gcc --output=type=image,push=false --platform linux/aarch64 -f ${{ steps.vars.outputs.DOCKERFILE }}.gcc
+      # TODO: add CI tag and test
+
       # Finally, assemble multi-arch image for a combined push to the registry
       #
       # This reruns docker build but layers are in the cache, so it's fast
@@ -225,12 +241,20 @@ jobs:
         run: |
           docker buildx build ${{ steps.vars.outputs.SRC }} --builder=container --cache-from=type=registry,ref=${{ steps.vars.outputs.IMAGE }}:${{ steps.vars.outputs.RELEASE_TAG }} --output=type=image,push=true --build-arg BUILDKIT_INLINE_CACHE=1 --platform ${{ steps.vars.outputs.DOCKER_PLATFORMS }} -f ${{ steps.vars.outputs.DOCKERFILE }} --tag ${{ steps.vars.outputs.IMAGE }}:${{ steps.vars.outputs.RELEASE_TAG }}
 
-      # TODO: hardcoded, reuse append-tags and strip-tags directives instead
+      # TODO: hardcoded, reuse strip-tags directive instead (or better, unify gnu)
       - name: Push unqualified release image (${{ join(matrix.arch, ', ') }})
         if: ${{ inputs.push && matrix.libc == 'gnu' }}
         run: |
           docker buildx build ${{ steps.vars.outputs.SRC }} --builder=container --cache-from=type=registry,ref=${{ steps.vars.outputs.IMAGE }}:${{ steps.vars.outputs.RELEASE_TAG }} --output=type=image,push=true --build-arg BUILDKIT_INLINE_CACHE=1 --platform ${{ steps.vars.outputs.DOCKER_PLATFORMS }} -f ${{ steps.vars.outputs.DOCKERFILE }} --tag ${{ steps.vars.outputs.IMAGE }}:${{ matrix.version }}
-      - name: Push compiler release image (${{ join(matrix.arch, ', ') }})
+
+      # TODO: hardcoded, reuse append-tags directive instead (or better, unify gnu)
+      - name: Push release compiler image (${{ join(matrix.arch, ', ') }})
         if: ${{ inputs.push && matrix.libc == 'gnu' }}
         run: |
-          docker buildx build ${{ steps.vars.outputs.SRC }} --builder=container --cache-from=type=registry,ref=${{ steps.vars.outputs.IMAGE }}:${{ steps.vars.outputs.RELEASE_TAG }} --output=type=image,push=true --build-arg BUILDKIT_INLINE_CACHE=1 --platform ${{ steps.vars.outputs.DOCKER_PLATFORMS }} -f ${{ steps.vars.outputs.DOCKERFILE }} --tag ${{ steps.vars.outputs.IMAGE }}:${{ steps.vars.outputs.RELEASE_TAG }}-gcc
+          docker buildx build ${{ steps.vars.outputs.SRC }} --builder=container --cache-from=type=registry,ref=${{ steps.vars.outputs.IMAGE }}:${{ steps.vars.outputs.RELEASE_TAG }}-gcc --output=type=image,push=true --build-arg BUILDKIT_INLINE_CACHE=1 --platform ${{ steps.vars.outputs.DOCKER_PLATFORMS }} -f ${{ steps.vars.outputs.DOCKERFILE }} --tag ${{ steps.vars.outputs.IMAGE }}:${{ steps.vars.outputs.RELEASE_TAG }}-gcc
+
+      # TODO: hardcoded musl, unify gnu instead
+      - name: Push release compiler image (${{ join(matrix.arch, ', ') }})
+        if: ${{ inputs.push && matrix.libc == 'musl' }}
+        run: |
+          docker buildx build ${{ steps.vars.outputs.SRC }} --builder=container --cache-from=type=registry,ref=${{ steps.vars.outputs.IMAGE }}:${{ steps.vars.outputs.RELEASE_TAG }}-gcc --output=type=image,push=true --build-arg BUILDKIT_INLINE_CACHE=1 --platform ${{ steps.vars.outputs.DOCKER_PLATFORMS }} -f ${{ steps.vars.outputs.DOCKERFILE }}.gcc --tag ${{ steps.vars.outputs.IMAGE }}:${{ steps.vars.outputs.RELEASE_TAG }}-gcc