diff --git a/.github/workflows/pr.yaml b/.github/workflows/pr.yaml
index 9c6c8556..5b1b9e7e 100644
--- a/.github/workflows/pr.yaml
+++ b/.github/workflows/pr.yaml
@@ -18,6 +18,7 @@ jobs:
       - devcontainer
       - detect-changes
       - test_benchmark_data_tools
+      - test_sccache_setup
     permissions:
       contents: read
     uses: rapidsai/shared-workflows/.github/workflows/pr-builder.yaml@main  # zizmor: ignore[unpinned-uses]
@@ -65,6 +66,7 @@ jobs:
     runs-on: ubuntu-latest
     outputs:
       benchmark_data_tools: ${{ steps.filter.outputs.benchmark_data_tools }}
+      sccache: ${{ steps.filter.outputs.sccache }}
     steps:
       - name: Checkout velox-testing
         uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd  # v6.0.2
@@ -78,6 +80,11 @@ jobs:
           filters: |
             benchmark_data_tools:
               - "benchmark_data_tools/**"
+            sccache:
+              - "scripts/sccache/sccache_setup.sh"
+              - "scripts/sccache/sccache_setup_test.sh"
+              - "presto/docker/native_build.dockerfile"
+              - "velox/docker/adapters_build.dockerfile"
 
   test_benchmark_data_tools:
     needs: detect-changes
@@ -93,3 +100,18 @@ jobs:
 
       - name: Test benchmark_data_tools
         uses: ./.github/actions/test-benchmark-data-tools
+
+  test_sccache_setup:
+    needs: detect-changes
+    if: ${{ needs.detect-changes.outputs.sccache == 'true' }}
+    permissions:
+      contents: read
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout velox-testing
+        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd  # v6.0.2
+        with:
+          persist-credentials: false
+
+      - name: Test sccache setup
+        run: bash scripts/sccache/sccache_setup_test.sh
diff --git a/presto/docker/native_build.dockerfile b/presto/docker/native_build.dockerfile
index a64f68a2..db237691 100644
--- a/presto/docker/native_build.dockerfile
+++ b/presto/docker/native_build.dockerfile
@@ -89,7 +89,8 @@ if [ "$ENABLE_SCCACHE" = "ON" ]; then
   if [ -n "${SCCACHE_NO_DIST_COMPILE:-}" ]; then
     export SCCACHE_NO_DIST_COMPILE=1;
   fi
-  bash /sccache_setup.sh;
+  # Source the setup so its automatic local-fallback export reaches the build.
+  source /sccache_setup.sh;
   EXTRA_CMAKE_FLAGS="${EXTRA_CMAKE_FLAGS} -DCMAKE_C_COMPILER_LAUNCHER=sccache -DCMAKE_CXX_COMPILER_LAUNCHER=sccache -DCMAKE_CUDA_COMPILER_LAUNCHER=sccache";
   export NVCC_APPEND_FLAGS="${NVCC_APPEND_FLAGS:+$NVCC_APPEND_FLAGS }-t=100";
 fi
diff --git a/scripts/sccache/sccache_setup.sh b/scripts/sccache/sccache_setup.sh
index b73e3210..f8f35dfe 100755
--- a/scripts/sccache/sccache_setup.sh
+++ b/scripts/sccache/sccache_setup.sh
@@ -18,7 +18,7 @@ chmod +x /usr/bin/sccache
 sccache --version
 
 # Increase file descriptor limit for high parallelism (as done in rapids-configure-sccache-dist)
-ulimit -n $(ulimit -Hn) || echo "Could not increase file descriptor limit"
+ulimit -n "$(ulimit -Hn)" || echo "Could not increase file descriptor limit"
 
 # Ensure sccache logfile directory exists
 mkdir -p "$(dirname "${SCCACHE_ERROR_LOG:-/tmp/sccache.log}")"
@@ -45,25 +45,38 @@ if ! test -v SCCACHE_NO_DIST_COMPILE; then
     echo "=== end diagnostics ==="
 fi
 
-sccache --zero-stats
-
 if test -v SCCACHE_NO_DIST_COMPILE; then
     echo "Distributed compilation is DISABLED - using local compilation with remote S3 caching"
 else
-    if sccache --dist-status 2>/dev/null | jq -er '.SchedulerStatus? != null' >/dev/null 2>&1; then
+    dist_status=""
+    server_count=""
+    if dist_status="$(sccache --dist-status 2>/dev/null)" \
+        && server_count="$(jq -er '(.SchedulerStatus?[1].servers? // []) | length' <<<"${dist_status}")" \
+        && (( server_count > 0 )); then
         echo "Distributed compilation is available:"
-        sccache --dist-status | jq -r '["scheduler URL: " + .SchedulerStatus[0], "server count: " + (.SchedulerStatus[1].servers | length | tostring)][]';
+        jq -r '["scheduler URL: " + .SchedulerStatus[0], "server count: " + (.SchedulerStatus[1].servers | length | tostring)][]' <<<"${dist_status}"
     else
-        echo "Error: Distributed compilation not available, check connectivity"
+        if [[ "${server_count}" == "0" ]]; then
+            echo "Error: Distributed compilation scheduler has no available servers"
+        else
+            echo "Error: Distributed compilation status unavailable, check connectivity"
+        fi
+        if [[ -n "${server_count}" ]]; then
+            echo "server count: ${server_count}"
+        fi
         if [[ -f "${SCCACHE_ERROR_LOG:-}" ]]; then
             echo "sccache error log:"
             cat "$SCCACHE_ERROR_LOG";
         fi
         if [[ "${SCCACHE_DIST_FALLBACK_TO_LOCAL_COMPILE:-false}" == "true" ]]; then
             echo "SCCACHE_DIST_FALLBACK_TO_LOCAL_COMPILE=true, continuing with local compilation"
+            # The Docker build callers source this script so this setting is
+            # inherited by every compiler request in the subsequent build.
             export SCCACHE_NO_DIST_COMPILE=1
         else
             exit 1
         fi
     fi
 fi
+
+sccache --zero-stats
diff --git a/scripts/sccache/sccache_setup_test.sh b/scripts/sccache/sccache_setup_test.sh
new file mode 100644
index 00000000..22bd623f
--- /dev/null
+++ b/scripts/sccache/sccache_setup_test.sh
@@ -0,0 +1,139 @@
+#!/bin/bash
+# SPDX-FileCopyrightText: Copyright (c) 2026, NVIDIA CORPORATION & AFFILIATES. All rights reserved.
+# SPDX-License-Identifier: Apache-2.0
+
+set -euo pipefail
+
+SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+REPOSITORY_ROOT="$(cd "${SCRIPT_DIR}/../.." && pwd)"
+SETUP_SCRIPT="${1:-${SCRIPT_DIR}/sccache_setup.sh}"
+TEST_ROOT="$(mktemp -d)"
+trap 'rm -rf "${TEST_ROOT}"' EXIT
+
+fail() {
+    echo "FAIL: $*" >&2
+    exit 1
+}
+
+assert_contains() {
+    local file="$1"
+    local expected="$2"
+    grep -Fq -- "${expected}" "${file}" \
+        || fail "Expected ${file} to contain: ${expected}"
+}
+
+run_setup_case() {
+    local name="$1"
+    local dist_status="$2"
+    local dist_status_exit_code="$3"
+    local fallback_enabled="$4"
+    local initially_disabled="$5"
+    local expected_exit_code="$6"
+    local expected_no_dist="$7"
+    local expected_status_calls="$8"
+
+    local case_dir="${TEST_ROOT}/${name}"
+    local output="${case_dir}/output"
+    local trace="${case_dir}/trace"
+    mkdir -p "${case_dir}"
+
+    local actual_exit_code=0
+    (
+        export SCCACHE_VERSION=test
+        export SCCACHE_ERROR_LOG="${case_dir}/sccache.log"
+        export SCCACHE_DIST_AUTH_TOKEN=test-token
+        export SCCACHE_DIST_FALLBACK_TO_LOCAL_COMPILE="${fallback_enabled}"
+        export TEST_DIST_STATUS="${dist_status}"
+        export TEST_DIST_STATUS_EXIT_CODE="${dist_status_exit_code}"
+        export TEST_SCCACHE_TRACE="${trace}"
+
+        if [[ "${initially_disabled}" == "true" ]]; then
+            export SCCACHE_NO_DIST_COMPILE=1
+        else
+            unset SCCACHE_NO_DIST_COMPILE
+        fi
+
+        # These mocks are called indirectly by the sourced setup script.
+        # shellcheck disable=SC2317
+        wget() {
+            return 0
+        }
+
+        # shellcheck disable=SC2317
+        tar() {
+            return 0
+        }
+
+        # shellcheck disable=SC2317
+        chmod() {
+            return 0
+        }
+
+        # shellcheck disable=SC2317
+        sccache() {
+            printf '%s|no_dist=%s\n' "$*" "${SCCACHE_NO_DIST_COMPILE:-}" \
+                >>"${TEST_SCCACHE_TRACE}"
+            case "${1:-}" in
+                --version)
+                    echo "sccache test"
+                    ;;
+                --stop-server | --zero-stats)
+                    ;;
+                --dist-status)
+                    if (( TEST_DIST_STATUS_EXIT_CODE != 0 )); then
+                        return "${TEST_DIST_STATUS_EXIT_CODE}"
+                    fi
+                    printf '%s\n' "${TEST_DIST_STATUS}"
+                    ;;
+                *)
+                    fail "Unexpected sccache arguments: $*"
+                    ;;
+            esac
+        }
+
+        # shellcheck disable=SC1090
+        source "${SETUP_SCRIPT}"
+        printf 'final_no_dist=%s\n' "${SCCACHE_NO_DIST_COMPILE:-unset}"
+    ) >"${output}" 2>&1 || actual_exit_code=$?
+
+    [[ "${actual_exit_code}" == "${expected_exit_code}" ]] \
+        || fail "${name}: expected exit ${expected_exit_code}, got ${actual_exit_code}"
+
+    local actual_status_calls
+    actual_status_calls="$(grep -c '^--dist-status|' "${trace}" || true)"
+    [[ "${actual_status_calls}" == "${expected_status_calls}" ]] \
+        || fail "${name}: expected ${expected_status_calls} status calls, got ${actual_status_calls}"
+
+    if [[ "${expected_exit_code}" == "0" ]]; then
+        assert_contains "${output}" "final_no_dist=${expected_no_dist}"
+    fi
+}
+
+healthy_status='{"SchedulerStatus":["https://arm64.example",{"servers":[{"id":"worker-1"}]}]}'
+empty_status='{"SchedulerStatus":["https://arm64.example",{"servers":[]}]}'
+
+run_setup_case healthy "${healthy_status}" 0 true false 0 unset 1
+assert_contains "${TEST_ROOT}/healthy/output" "server count: 1"
+
+run_setup_case zero-workers "${empty_status}" 0 true false 0 1 1
+assert_contains "${TEST_ROOT}/zero-workers/output" "scheduler has no available servers"
+assert_contains "${TEST_ROOT}/zero-workers/output" "server count: 0"
+assert_contains "${TEST_ROOT}/zero-workers/trace" "--zero-stats|no_dist=1"
+
+run_setup_case status-error '{}' 1 true false 0 1 1
+run_setup_case missing-status '{}' 0 true false 0 1 1
+run_setup_case invalid-status 'not-json' 0 true false 0 1 1
+run_setup_case fallback-disabled "${empty_status}" 0 false false 1 unset 1
+run_setup_case explicitly-disabled "${empty_status}" 0 true true 0 1 0
+
+for dockerfile in \
+    "${REPOSITORY_ROOT}/presto/docker/native_build.dockerfile" \
+    "${REPOSITORY_ROOT}/velox/docker/adapters_build.dockerfile"
+do
+    assert_contains "${dockerfile}" "source /sccache_setup.sh;"
+    if grep -Fq "bash /sccache_setup.sh;" "${dockerfile}"; then
+        fail "${dockerfile} runs sccache setup in a child shell"
+    fi
+done
+
+echo "All sccache setup tests passed"
diff --git a/velox/docker/adapters_build.dockerfile b/velox/docker/adapters_build.dockerfile
index 635bdc52..3b480fd7 100644
--- a/velox/docker/adapters_build.dockerfile
+++ b/velox/docker/adapters_build.dockerfile
@@ -163,7 +163,8 @@ if [ "$ENABLE_SCCACHE" = "ON" ]; then
   if [ -n "${SCCACHE_NO_DIST_COMPILE:-}" ]; then
     export SCCACHE_NO_DIST_COMPILE=1;
   fi
-  bash /sccache_setup.sh;
+  # Source the setup so its automatic local-fallback export reaches the build.
+  source /sccache_setup.sh;
   EXTRA_CMAKE_FLAGS="${EXTRA_CMAKE_FLAGS} -DCMAKE_C_COMPILER_LAUNCHER=sccache -DCMAKE_CXX_COMPILER_LAUNCHER=sccache -DCMAKE_CUDA_COMPILER_LAUNCHER=sccache";
   export NVCC_APPEND_FLAGS="${NVCC_APPEND_FLAGS:+$NVCC_APPEND_FLAGS }-t=100";
 fi