docker/unified: vulkan build fixes (#600)

multiple fixes to vulkan build: 

- use ubuntu 26.04 to be compatible with AMD 395+ (Strix halo) hardware
- add home directory in container 
- fix stable-diffusion install to actually enable vulkan

---------

Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>

.github/workflows/unified-docker.yml

@@ -22,6 +22,16 @@ on:
         description: "llama-swap version (e.g. v198, latest, main)"
         required: false
         default: "main"
+      build_cuda:
+        description: "Build CUDA image"
+        type: boolean
+        required: false
+        default: true
+      build_vulkan:
+        description: "Build Vulkan image"
+        type: boolean
+        required: false
+        default: true
 
 permissions:
   contents: read
@@ -33,7 +43,12 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        backend: [cuda, vulkan]
+        backend:
+          - cuda
+          - vulkan
+        exclude:
+          - backend: ${{ inputs.build_cuda == false && 'cuda' || 'none' }}
+          - backend: ${{ inputs.build_vulkan == false && 'vulkan' || 'none' }}
     steps:
       - name: Checkout code
         uses: actions/checkout@v4

docker/unified/Dockerfile

@@ -29,7 +29,7 @@ WORKDIR /build
 
 # ──
 
-FROM ubuntu:22.04 AS builder-base-vulkan
+FROM ubuntu:26.04 AS builder-base-vulkan
 
 ENV DEBIAN_FRONTEND=noninteractive
 ENV CCACHE_DIR=/ccache
@@ -39,12 +39,7 @@ ENV PATH="/usr/lib/ccache:${PATH}"
 RUN apt-get update && apt-get install -y --no-install-recommends \
     build-essential cmake git python3 python3-pip libssl-dev \
     curl ca-certificates ccache make wget software-properties-common \
-    && rm -rf /var/lib/apt/lists/*
-
-# Install LunarG Vulkan SDK (Ubuntu 22.04 repo headers are too old)
-RUN wget -qO /etc/apt/trusted.gpg.d/lunarg.asc https://packages.lunarg.com/lunarg-signing-key-pub.asc \
-    && echo "deb https://packages.lunarg.com/vulkan jammy main" > /etc/apt/sources.list.d/lunarg-vulkan.list \
-    && apt-get update && apt-get install -y --no-install-recommends vulkan-sdk \
+    libvulkan-dev glslang-tools spirv-tools vulkan-validationlayers glslc \
     && rm -rf /var/lib/apt/lists/*
 
 WORKDIR /build
@@ -108,7 +103,7 @@ COPY --from=builder-base-cuda /usr/local/cuda/lib64/stubs/libcuda.so /usr/local/
 
 # ──
 
-FROM ubuntu:22.04 AS runtime-vulkan
+FROM ubuntu:26.04 AS runtime-vulkan
 
 ENV DEBIAN_FRONTEND=noninteractive
 ENV PATH="/usr/local/bin:${PATH}"
@@ -127,10 +122,10 @@ ARG LLAMA_COMMIT_HASH=unknown
 ARG WHISPER_COMMIT_HASH=unknown
 ARG SD_COMMIT_HASH=unknown
 
-RUN pip3 install --no-cache-dir numpy sentencepiece
+RUN pip3 install --no-cache-dir --break-system-packages numpy sentencepiece
 
 # Create llama-swap user and config directory
-RUN useradd --system --no-create-home --shell /sbin/nologin llama-swap && \
+RUN useradd --system --create-home --shell /sbin/nologin llama-swap && \
     mkdir -p /etc/llama-swap/config && \
     chown -R llama-swap:llama-swap /etc/llama-swap
 

docker/unified/install-sd.sh

@@ -43,6 +43,7 @@ elif [ "$BACKEND" = "vulkan" ]; then
     CMAKE_FLAGS+=(
         -DGGML_CUDA=OFF
         -DGGML_VULKAN=ON
+        -DSD_VULKAN=ON
     )
 fi