diff --git a/config/docker/cli-launch-contract/Dockerfile b/config/docker/cli-launch-contract/Dockerfile
index f6a618a8ece..c90cbcd979c 100644
--- a/config/docker/cli-launch-contract/Dockerfile
+++ b/config/docker/cli-launch-contract/Dockerfile
@@ -6,8 +6,13 @@ ARG LIBASOUND_PACKAGE=libasound2t64
 ENV DEBIAN_FRONTEND=noninteractive
 
 # Install Electron's link-time libraries without adding a display server or FUSE.
-RUN apt-get update \
-  && apt-get install -y --no-install-recommends \
+# Why: archive.ubuntu.com mid-sync returns Hash Sum mismatch / wrong-size indexes and stalls per-package fetches; retry with bounded timeouts and drop half-synced lists between attempts.
+RUN for attempt in 1 2 3 4 5; do \
+      apt-get -o Acquire::Retries=5 -o Acquire::http::Timeout=30 update && break; \
+      if [ "$attempt" = 5 ]; then exit 100; fi; \
+      rm -rf /var/lib/apt/lists/*; sleep 20; \
+    done \
+  && apt-get -o Acquire::Retries=5 -o Acquire::http::Timeout=30 install -y --no-install-recommends \
     bash \
     ca-certificates \
     coreutils \
diff --git a/config/docker/headless-pairing/Dockerfile b/config/docker/headless-pairing/Dockerfile
index 03664f68b0d..e4b4cafeefc 100644
--- a/config/docker/headless-pairing/Dockerfile
+++ b/config/docker/headless-pairing/Dockerfile
@@ -5,8 +5,13 @@ ARG LIBASOUND_PACKAGE=libasound2t64
 
 ENV DEBIAN_FRONTEND=noninteractive
 
-RUN apt-get update \
-  && apt-get install -y --no-install-recommends \
+# Why: archive.ubuntu.com mid-sync returns Hash Sum mismatch / wrong-size indexes and stalls per-package fetches; retry with bounded timeouts and drop half-synced lists between attempts.
+RUN for attempt in 1 2 3 4 5; do \
+      apt-get -o Acquire::Retries=5 -o Acquire::http::Timeout=30 update && break; \
+      if [ "$attempt" = 5 ]; then exit 100; fi; \
+      rm -rf /var/lib/apt/lists/*; sleep 20; \
+    done \
+  && apt-get -o Acquire::Retries=5 -o Acquire::http::Timeout=30 install -y --no-install-recommends \
     bash \
     ca-certificates \
     dbus-x11 \
diff --git a/config/docker/headless-serve-shutdown/Dockerfile b/config/docker/headless-serve-shutdown/Dockerfile
index 13b1ed2b69f..8ee7b942499 100644
--- a/config/docker/headless-serve-shutdown/Dockerfile
+++ b/config/docker/headless-serve-shutdown/Dockerfile
@@ -2,8 +2,13 @@ FROM ubuntu@sha256:678c6550cc43645e08669028bc177f50be4e7c5b8cca677067b1914d4afc7
 
 ENV DEBIAN_FRONTEND=noninteractive
 
-RUN apt-get update \
-  && apt-get install -y --no-install-recommends \
+# Why: archive.ubuntu.com mid-sync returns Hash Sum mismatch / wrong-size indexes and stalls per-package fetches; retry with bounded timeouts and drop half-synced lists between attempts.
+RUN for attempt in 1 2 3 4 5; do \
+      apt-get -o Acquire::Retries=5 -o Acquire::http::Timeout=30 update && break; \
+      if [ "$attempt" = 5 ]; then exit 100; fi; \
+      rm -rf /var/lib/apt/lists/*; sleep 20; \
+    done \
+  && apt-get -o Acquire::Retries=5 -o Acquire::http::Timeout=30 install -y --no-install-recommends \
     bash \
     ca-certificates \
     dbus-x11 \
diff --git a/config/scripts/run-headless-linux-pairing-docker.mjs b/config/scripts/run-headless-linux-pairing-docker.mjs
index 635c66348cc..799b8d73ab1 100644
--- a/config/scripts/run-headless-linux-pairing-docker.mjs
+++ b/config/scripts/run-headless-linux-pairing-docker.mjs
@@ -70,7 +70,7 @@ function valueAfter(flag) {
 
 function buildImage(image) {
   console.log(`Building ${image.name} fixture...`)
-  docker([
+  const buildArgs = [
     'build',
     '--build-arg',
     `BASE_IMAGE=${image.base}`,
@@ -81,7 +81,16 @@ function buildImage(image) {
     '-t',
     image.tag,
     '.'
-  ])
+  ]
+  // Why: apt fetches from archive.ubuntu.com stall or fail mid-sync; a second build usually lands on a healthy index.
+  try {
+    docker(buildArgs)
+  } catch (error) {
+    console.error(
+      `${error instanceof Error ? error.message : String(error)}\nRetrying docker build once...`
+    )
+    docker(buildArgs)
+  }
 }
 
 function extractAppImage(image) {
diff --git a/config/scripts/run-headless-serve-shutdown-docker.mjs b/config/scripts/run-headless-serve-shutdown-docker.mjs
index 184713c41a0..d8dcdd345ad 100755
--- a/config/scripts/run-headless-serve-shutdown-docker.mjs
+++ b/config/scripts/run-headless-serve-shutdown-docker.mjs
@@ -43,7 +43,7 @@ const artifactVolume = `orca-headless-serve-shutdown-${suffix}`
 const sha256 = createHash('sha256').update(readFileSync(appImage)).digest('hex')
 
 try {
-  docker([
+  const buildArgs = [
     'build',
     '--platform',
     platform,
@@ -52,7 +52,15 @@ try {
     '-t',
     image,
     shutdownDockerDirectory
-  ])
+  ]
+  // Why: apt fetches from archive.ubuntu.com stall or fail mid-sync; a second build usually lands on a healthy index.
+  const firstBuild = docker(buildArgs, { allowFailure: true })
+  if (firstBuild.status !== 0) {
+    process.stderr.write(
+      `${firstBuild.stdout}${firstBuild.stderr}\ndocker build failed with status ${firstBuild.status}; retrying once...\n`
+    )
+    docker(buildArgs)
+  }
   docker(['volume', 'create', artifactVolume])
   runDesktopStartupOracle({ image, appImage, platform })
   docker([
diff --git a/config/scripts/run-linux-cli-launch-contract-docker.mjs b/config/scripts/run-linux-cli-launch-contract-docker.mjs
index 901e0877e85..bd414947026 100755
--- a/config/scripts/run-linux-cli-launch-contract-docker.mjs
+++ b/config/scripts/run-linux-cli-launch-contract-docker.mjs
@@ -173,20 +173,26 @@ function runCase(caseName) {
 
 function buildImage() {
   console.log(`Building ${tag}…`)
-  docker(
-    [
-      'build',
-      ...dockerPlatformArgs,
-      '--build-arg',
-      `BASE_IMAGE=${base}`,
-      '-f',
-      'config/docker/cli-launch-contract/Dockerfile',
-      '-t',
-      tag,
-      'config/docker/cli-launch-contract'
-    ],
-    { timeoutMs: BUILD_TIMEOUT_MS }
-  )
+  const buildArgs = [
+    'build',
+    ...dockerPlatformArgs,
+    '--build-arg',
+    `BASE_IMAGE=${base}`,
+    '-f',
+    'config/docker/cli-launch-contract/Dockerfile',
+    '-t',
+    tag,
+    'config/docker/cli-launch-contract'
+  ]
+  // Why: apt fetches from archive.ubuntu.com stall or fail mid-sync; a second build usually lands on a healthy index.
+  try {
+    docker(buildArgs, { timeoutMs: BUILD_TIMEOUT_MS })
+  } catch (error) {
+    console.error(
+      `${error instanceof Error ? error.message : String(error)}\nRetrying docker build once…`
+    )
+    docker(buildArgs, { timeoutMs: BUILD_TIMEOUT_MS })
+  }
 }
 
 // Extract unprivileged so chrome-sandbox is not root-owned setuid.