[update] diagnostic message when gpu adapter instantiation fails & update how mesa is installed and configured in our pipelines

Author: vmarcella

.github/workflows/compile_lambda_rs.yml

@@ -72,8 +72,22 @@ jobs:
         if: ${{ matrix.os == 'ubuntu-latest' }}
         run: |
           echo "WGPU_BACKEND=vulkan" >> "$GITHUB_ENV"
-          # Prefer Mesa's software Vulkan (lavapipe) to ensure headless availability
-          echo "VK_ICD_FILENAMES=/usr/share/vulkan/icd.d/lvp_icd.x86_64.json" >> "$GITHUB_ENV"
+          # Prefer Mesa's software Vulkan (lavapipe) to ensure headless availability.
+          # The exact ICD filename can differ across Ubuntu images, so discover it.
+          LVP_ICD="$(
+            if [[ -d /usr/share/vulkan/icd.d ]]; then
+              find /usr/share/vulkan/icd.d -maxdepth 1 -type f \
+                \( -name '*lvp_icd*.json' -o -name '*lavapipe*.json' \) \
+                -print 2>/dev/null | head -n1
+            fi
+          )"
+          if [[ -z "$LVP_ICD" ]]; then
+            echo "lavapipe Vulkan ICD not found under /usr/share/vulkan/icd.d" >&2
+            ls -la /usr/share/vulkan/icd.d || true
+          else
+            echo "Using lavapipe ICD: $LVP_ICD"
+            echo "VK_ICD_FILENAMES=$LVP_ICD" >> "$GITHUB_ENV"
+          fi
           echo "LAMBDA_REQUIRE_GPU_ADAPTER=1" >> "$GITHUB_ENV"
           vulkaninfo --summary || true
 

.github/workflows/coverage.yml

@@ -62,8 +62,22 @@ jobs:
       - name: Configure Vulkan (Ubuntu)
         run: |
           echo "WGPU_BACKEND=vulkan" >> "$GITHUB_ENV"
-          # Prefer Mesa's software Vulkan (lavapipe) for headless availability
-          echo "VK_ICD_FILENAMES=/usr/share/vulkan/icd.d/lvp_icd.x86_64.json" >> "$GITHUB_ENV"
+          # Prefer Mesa's software Vulkan (lavapipe) for headless availability.
+          # The exact ICD filename can differ across Ubuntu images, so discover it.
+          LVP_ICD="$(
+            if [[ -d /usr/share/vulkan/icd.d ]]; then
+              find /usr/share/vulkan/icd.d -maxdepth 1 -type f \
+                \( -name '*lvp_icd*.json' -o -name '*lavapipe*.json' \) \
+                -print 2>/dev/null | head -n1
+            fi
+          )"
+          if [[ -z "$LVP_ICD" ]]; then
+            echo "lavapipe Vulkan ICD not found under /usr/share/vulkan/icd.d" >&2
+            ls -la /usr/share/vulkan/icd.d || true
+          else
+            echo "Using lavapipe ICD: $LVP_ICD"
+            echo "VK_ICD_FILENAMES=$LVP_ICD" >> "$GITHUB_ENV"
+          fi
           vulkaninfo --summary || true
 
       - name: Generate full coverage JSON

.github/workflows/release.yml

@@ -53,7 +53,22 @@ jobs:
       - name: Configure Vulkan for headless CI
         run: |
           echo "WGPU_BACKEND=vulkan" >> "$GITHUB_ENV"
-          echo "VK_ICD_FILENAMES=/usr/share/vulkan/icd.d/lvp_icd.x86_64.json" >> "$GITHUB_ENV"
+          # Prefer Mesa's software Vulkan (lavapipe) for headless availability.
+          # The exact ICD filename can differ across Ubuntu images, so discover it.
+          LVP_ICD="$(
+            if [[ -d /usr/share/vulkan/icd.d ]]; then
+              find /usr/share/vulkan/icd.d -maxdepth 1 -type f \
+                \( -name '*lvp_icd*.json' -o -name '*lavapipe*.json' \) \
+                -print 2>/dev/null | head -n1
+            fi
+          )"
+          if [[ -z "$LVP_ICD" ]]; then
+            echo "lavapipe Vulkan ICD not found under /usr/share/vulkan/icd.d" >&2
+            ls -la /usr/share/vulkan/icd.d || true
+          else
+            echo "Using lavapipe ICD: $LVP_ICD"
+            echo "VK_ICD_FILENAMES=$LVP_ICD" >> "$GITHUB_ENV"
+          fi
           echo "LAMBDA_REQUIRE_GPU_ADAPTER=1" >> "$GITHUB_ENV"
           vulkaninfo --summary || true
 

crates/lambda-rs/src/render/gpu.rs

@@ -275,27 +275,33 @@ pub(crate) fn create_test_gpu_with_instance(
   instance: &Instance,
   label_base: &str,
 ) -> Option<Gpu> {
-  let built = GpuBuilder::new()
+  let primary_err = match GpuBuilder::new()
     .with_label(&format!("{}-gpu", label_base))
     .build(instance, None)
-    .ok();
-  if built.is_some() {
-    return built;
-  }
+  {
+    Ok(gpu) => return Some(gpu),
+    Err(err) => err,
+  };
 
-  let fallback = GpuBuilder::new()
+  let fallback_err = match GpuBuilder::new()
     .with_label(&format!("{}-gpu-fallback", label_base))
     .force_fallback(true)
     .build(instance, None)
-    .ok();
+  {
+    Ok(gpu) => return Some(gpu),
+    Err(err) => err,
+  };
 
-  if fallback.is_none() && require_gpu_adapter_for_tests() {
+  if require_gpu_adapter_for_tests() {
     panic!(
-      "No GPU adapter available for tests (set LAMBDA_REQUIRE_GPU_ADAPTER=0 to allow skipping)"
+      "No GPU adapter available for tests (label_base={}).\nPrimary adapter attempt: {}\nFallback adapter attempt: {}\n(Set LAMBDA_REQUIRE_GPU_ADAPTER=0 to allow skipping)",
+      label_base,
+      primary_err,
+      fallback_err,
     );
   }
 
-  return fallback;
+  return None;
 }
 
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