diff --git a/start-test-validator/action.yaml b/start-test-validator/action.yaml
index 4480ff5..1531310 100644
--- a/start-test-validator/action.yaml
+++ b/start-test-validator/action.yaml
@@ -24,7 +24,7 @@ runs:
   steps:
     - name: Start validator
       id: start
-      shell: bash
+      shell: bash -euo pipefail {0}
       env:
         LEDGER_DIR_INPUT: ${{ inputs.ledger-dir }}
       run: |
diff --git a/write-program-buffer/tests/integration/assert-authority.sh b/write-program-buffer/tests/integration/assert-authority.sh
index 9ac05da..7d1251a 100755
--- a/write-program-buffer/tests/integration/assert-authority.sh
+++ b/write-program-buffer/tests/integration/assert-authority.sh
@@ -15,7 +15,8 @@ fail() {
 
 BUFFER_INFO=$(solana program show "$BUFFER" -u "$RPC_URL")
 echo "$BUFFER_INFO"
-AUTHORITY=$(echo "$BUFFER_INFO" | grep "Authority:" | awk '{print $2}')
+AUTHORITY=$(echo "$BUFFER_INFO" | grep "Authority:" | awk '{print $2}' || true)
+[ -n "$AUTHORITY" ] || fail "could not read authority of buffer $BUFFER"
 [ "$AUTHORITY" = "$BUFFER_AUTHORITY" ] || fail "buffer authority is $AUTHORITY, expected $BUFFER_AUTHORITY"
 [ "$AUTHORITY" != "$DEPLOYER" ] || fail "buffer authority still equals the deployer"
 
diff --git a/write-program-buffer/tests/integration/assert-clamp.sh b/write-program-buffer/tests/integration/assert-clamp.sh
index 44bb03f..2f05d9d 100755
--- a/write-program-buffer/tests/integration/assert-clamp.sh
+++ b/write-program-buffer/tests/integration/assert-clamp.sh
@@ -14,7 +14,8 @@ fail() {
 [ -n "${PROGRAM_ID:-}" ] || fail "PROGRAM_ID env not set"
 [ -n "${PRE_LEN:-}" ] || fail "PRE_LEN env not set"
 
-POST_LEN=$(solana program show "$PROGRAM_ID" -u "$RPC_URL" | grep "Data Length:" | sed -E 's/.*Data Length: ([0-9]+).*/\1/' | cut -d ' ' -f1)
+POST_LEN=$(solana program show "$PROGRAM_ID" -u "$RPC_URL" | grep "Data Length:" | sed -E 's/.*Data Length: ([0-9]+).*/\1/' | cut -d ' ' -f1 || true)
+[ -n "$POST_LEN" ] || fail "could not read data length of program $PROGRAM_ID"
 GROWTH=$((POST_LEN - PRE_LEN))
 [ "$GROWTH" -eq "$MIN_EXTEND_SIZE" ] || fail "program grew by $GROWTH bytes, expected exactly $MIN_EXTEND_SIZE"
 
diff --git a/write-program-buffer/tests/integration/assert-delta.sh b/write-program-buffer/tests/integration/assert-delta.sh
index 8ce2731..2ea878f 100755
--- a/write-program-buffer/tests/integration/assert-delta.sh
+++ b/write-program-buffer/tests/integration/assert-delta.sh
@@ -18,7 +18,8 @@ REQUIRED_SIZE=$(wc -c < "$ARTIFACT" | tr -d ' ')
 EXPECTED_GROWTH=$((REQUIRED_SIZE - PRE_LEN))
 [ "$EXPECTED_GROWTH" -gt "$MIN_EXTEND_SIZE" ] || fail "scenario setup invalid: expected growth $EXPECTED_GROWTH must exceed $MIN_EXTEND_SIZE"
 
-POST_LEN=$(solana program show "$PROGRAM_ID" -u "$RPC_URL" | grep "Data Length:" | sed -E 's/.*Data Length: ([0-9]+).*/\1/' | cut -d ' ' -f1)
+POST_LEN=$(solana program show "$PROGRAM_ID" -u "$RPC_URL" | grep "Data Length:" | sed -E 's/.*Data Length: ([0-9]+).*/\1/' | cut -d ' ' -f1 || true)
+[ -n "$POST_LEN" ] || fail "could not read data length of program $PROGRAM_ID"
 GROWTH=$((POST_LEN - PRE_LEN))
 [ "$GROWTH" -eq "$EXPECTED_GROWTH" ] || fail "program grew by $GROWTH bytes, expected the exact delta $EXPECTED_GROWTH"
 
diff --git a/write-program-buffer/tests/integration/assert-fresh.sh b/write-program-buffer/tests/integration/assert-fresh.sh
index 31d3e88..fc57bfa 100755
--- a/write-program-buffer/tests/integration/assert-fresh.sh
+++ b/write-program-buffer/tests/integration/assert-fresh.sh
@@ -20,7 +20,8 @@ rm -f "$DUMP"
 
 BUFFER_INFO=$(solana program show "$BUFFER" -u "$RPC_URL")
 echo "$BUFFER_INFO"
-AUTHORITY=$(echo "$BUFFER_INFO" | grep "Authority:" | awk '{print $2}')
+AUTHORITY=$(echo "$BUFFER_INFO" | grep "Authority:" | awk '{print $2}' || true)
+[ -n "$AUTHORITY" ] || fail "could not read authority of buffer $BUFFER"
 [ "$AUTHORITY" = "$DEPLOYER" ] || fail "buffer authority is $AUTHORITY, expected deployer $DEPLOYER"
 
 ABSENCE_CHECK=$(solana program show "$PROGRAM_ID" -u "$RPC_URL" 2>&1 || true)
diff --git a/write-program-buffer/tests/integration/assert-nearmax.sh b/write-program-buffer/tests/integration/assert-nearmax.sh
index 6138c73..8882839 100755
--- a/write-program-buffer/tests/integration/assert-nearmax.sh
+++ b/write-program-buffer/tests/integration/assert-nearmax.sh
@@ -16,7 +16,8 @@ fail() {
 [ -n "${PROGRAM_ID:-}" ] || fail "PROGRAM_ID env not set"
 [ -n "${PRE_LEN:-}" ] || fail "PRE_LEN env not set"
 
-POST_LEN=$(solana program show "$PROGRAM_ID" -u "$RPC_URL" | grep "Data Length:" | sed -E 's/.*Data Length: ([0-9]+).*/\1/' | cut -d ' ' -f1)
+POST_LEN=$(solana program show "$PROGRAM_ID" -u "$RPC_URL" | grep "Data Length:" | sed -E 's/.*Data Length: ([0-9]+).*/\1/' | cut -d ' ' -f1 || true)
+[ -n "$POST_LEN" ] || fail "could not read data length of program $PROGRAM_ID"
 [ "$POST_LEN" -eq "$MAX_PROGRAM_SIZE" ] || fail "program data length is $POST_LEN, expected the exact maximum $MAX_PROGRAM_SIZE"
 echo "Program extended from $PRE_LEN to $POST_LEN (exact headroom of $((POST_LEN - PRE_LEN)) bytes)"
 
diff --git a/write-program-buffer/tests/integration/prepare-clamp.sh b/write-program-buffer/tests/integration/prepare-clamp.sh
index 24073f5..a327bdb 100755
--- a/write-program-buffer/tests/integration/prepare-clamp.sh
+++ b/write-program-buffer/tests/integration/prepare-clamp.sh
@@ -34,7 +34,7 @@ solana program deploy "$FIXTURES_DIR/program-small.so" \
   -u "$RPC_URL" -k "$SCENARIO_DIR/deployer.json" \
   --commitment confirmed
 
-PRE_LEN=$(solana program show "$PROGRAM_ID" -u "$RPC_URL" | grep "Data Length:" | sed -E 's/.*Data Length: ([0-9]+).*/\1/' | cut -d ' ' -f1)
+PRE_LEN=$(solana program show "$PROGRAM_ID" -u "$RPC_URL" | grep "Data Length:" | sed -E 's/.*Data Length: ([0-9]+).*/\1/' | cut -d ' ' -f1 || true)
 if [ -z "$PRE_LEN" ]; then
   echo "Could not read deployed program size" >&2
   exit 1
diff --git a/write-program-buffer/tests/integration/prepare-delta.sh b/write-program-buffer/tests/integration/prepare-delta.sh
index 3d1d7ac..542377e 100755
--- a/write-program-buffer/tests/integration/prepare-delta.sh
+++ b/write-program-buffer/tests/integration/prepare-delta.sh
@@ -35,7 +35,7 @@ solana program deploy "$FIXTURES_DIR/program-small.so" \
   -u "$RPC_URL" -k "$SCENARIO_DIR/deployer.json" \
   --commitment confirmed
 
-PRE_LEN=$(solana program show "$PROGRAM_ID" -u "$RPC_URL" | grep "Data Length:" | sed -E 's/.*Data Length: ([0-9]+).*/\1/' | cut -d ' ' -f1)
+PRE_LEN=$(solana program show "$PROGRAM_ID" -u "$RPC_URL" | grep "Data Length:" | sed -E 's/.*Data Length: ([0-9]+).*/\1/' | cut -d ' ' -f1 || true)
 if [ -z "$PRE_LEN" ]; then
   echo "Could not read deployed program size" >&2
   exit 1
diff --git a/write-program-buffer/tests/integration/prepare-nearmax.sh b/write-program-buffer/tests/integration/prepare-nearmax.sh
index 09fab15..bc6c412 100755
--- a/write-program-buffer/tests/integration/prepare-nearmax.sh
+++ b/write-program-buffer/tests/integration/prepare-nearmax.sh
@@ -46,11 +46,15 @@ solana program deploy "$FIXTURES_DIR/program-small.so" \
   --commitment confirmed
 
 read_data_len() {
-  solana program show "$PROGRAM_ID" -u "$RPC_URL" | grep "Data Length:" | sed -E 's/.*Data Length: ([0-9]+).*/\1/' | cut -d ' ' -f1
+  solana program show "$PROGRAM_ID" -u "$RPC_URL" | grep "Data Length:" | sed -E 's/.*Data Length: ([0-9]+).*/\1/' | cut -d ' ' -f1 || true
 }
 
 for i in 1 2 3; do
   CURRENT_LEN=$(read_data_len)
+  if [ -z "$CURRENT_LEN" ]; then
+    echo "Could not read program data length for $PROGRAM_ID" >&2
+    exit 1
+  fi
   REMAINING=$((TARGET_CURRENT - CURRENT_LEN))
   if [ "$REMAINING" -le 0 ]; then
     break
@@ -66,6 +70,10 @@ for i in 1 2 3; do
 done
 
 PRE_LEN=$(read_data_len)
+if [ -z "$PRE_LEN" ]; then
+  echo "Could not read program data length for $PROGRAM_ID" >&2
+  exit 1
+fi
 if [ "$PRE_LEN" -ne "$TARGET_CURRENT" ]; then
   echo "Setup failed: program data length is $PRE_LEN, expected $TARGET_CURRENT" >&2
   exit 1