diff --git a/.clang-tidy b/.clang-tidy
index 9c541aa..c8fe523 100644
--- a/.clang-tidy
+++ b/.clang-tidy
@@ -187,6 +187,7 @@
 clang-analyzer-webkit.RefCntblBaseVirtualDtor,
 cppcoreguidelines-avoid-c-arrays,
 cppcoreguidelines-init-variables,
+cppcoreguidelines-pro-type-vararg,
 misc-misplaced-const,
 misc-redundant-expression,
 misc-static-assert,
diff --git a/src/ADCSensor.cpp b/src/ADCSensor.cpp
index 0638b7d..a8287b4 100644
--- a/src/ADCSensor.cpp
+++ b/src/ADCSensor.cpp
@@ -54,11 +54,19 @@
            maxVoltageReading / scaleFactor, minVoltageReading / scaleFactor,
            conn, readState),
     std::enable_shared_from_this<ADCSensor>(), objServer(objectServer),
-    inputDev(io, open(path.c_str(), O_RDONLY)), waitTimer(io), path(path),
-    scaleFactor(scaleFactor),
+    inputDev(io), waitTimer(io), path(path), scaleFactor(scaleFactor),
     sensorPollMs(static_cast<unsigned int>(pollRate * 1000)),
     bridgeGpio(std::move(bridgeGpio)), thresholdTimer(io)
 {
+    // NOLINTNEXTLINE(cppcoreguidelines-pro-type-vararg)
+    int fd = open(path.c_str(), O_RDONLY);
+    if (fd < 0)
+    {
+        std::cerr << "unable to open acd device \n";
+    }
+
+    inputDev.assign(fd);
+
     sensorInterface = objectServer.add_interface(
         "/xyz/openbmc_project/sensors/voltage/" + name,
         "xyz.openbmc_project.Sensor.Value");
@@ -183,6 +191,8 @@
     {
         (*bridgeGpio).set(0);
     }
+
+    // NOLINTNEXTLINE(cppcoreguidelines-pro-type-vararg)
     int fd = open(path.c_str(), O_RDONLY);
     if (fd < 0)
     {
diff --git a/src/CPUSensor.cpp b/src/CPUSensor.cpp
index 6154b6f..0fdb2f4 100644
--- a/src/CPUSensor.cpp
+++ b/src/CPUSensor.cpp
@@ -117,6 +117,8 @@
     if (readingStateGood())
     {
         inputDev.close();
+
+        // NOLINTNEXTLINE(cppcoreguidelines-pro-type-vararg)
         int fd = open(path.c_str(), O_RDONLY);
         if (fd >= 0)
         {
diff --git a/src/CPUSensorMain.cpp b/src/CPUSensorMain.cpp
index fd9e543..4f377aa 100644
--- a/src/CPUSensorMain.cpp
+++ b/src/CPUSensorMain.cpp
@@ -463,6 +463,8 @@
     for (CPUConfig& config : cpuConfigs)
     {
         std::string peciDevPath = peciDev + std::to_string(config.bus);
+
+        // NOLINTNEXTLINE(cppcoreguidelines-pro-type-vararg)
         auto file = open(peciDevPath.c_str(), O_RDWR | O_CLOEXEC);
         if (file < 0)
         {
@@ -474,6 +476,8 @@
         struct peci_ping_msg msg
         {};
         msg.addr = config.addr;
+
+        // NOLINTNEXTLINE(cppcoreguidelines-pro-type-vararg)
         if (!ioctl(file, PECI_IOC_PING, &msg))
         {
             bool dimmReady = false;
@@ -485,6 +489,8 @@
                 msg.index = PECI_MBX_INDEX_DDR_DIMM_TEMP;
                 msg.param = rank;
                 msg.rx_len = 4;
+
+                // NOLINTNEXTLINE(cppcoreguidelines-pro-type-vararg)
                 if (!ioctl(file, PECI_IOC_RD_PKG_CFG, &msg))
                 {
                     if (msg.pkg_config[0] || msg.pkg_config[1] ||
diff --git a/src/ChassisIntrusionSensor.cpp b/src/ChassisIntrusionSensor.cpp
index 4b89709..9b35da2 100644
--- a/src/ChassisIntrusionSensor.cpp
+++ b/src/ChassisIntrusionSensor.cpp
@@ -80,12 +80,15 @@
 {
     std::string i2cBus = "/dev/i2c-" + std::to_string(busId);
 
+    // NOLINTNEXTLINE(cppcoreguidelines-pro-type-vararg)
     int fd = open(i2cBus.c_str(), O_RDWR | O_CLOEXEC);
     if (fd < 0)
     {
         std::cerr << "unable to open i2c device \n";
         return -1;
     }
+
+    // NOLINTNEXTLINE(cppcoreguidelines-pro-type-vararg)
     if (ioctl(fd, I2C_SLAVE_FORCE, slaveAddr) < 0)
     {
         std::cerr << "unable to set device address\n";
@@ -94,6 +97,8 @@
     }
 
     unsigned long funcs = 0;
+
+    // NOLINTNEXTLINE(cppcoreguidelines-pro-type-vararg)
     if (ioctl(fd, I2C_FUNCS, &funcs) < 0)
     {
         std::cerr << "not support I2C_FUNCS \n";
diff --git a/src/HwmonTempSensor.cpp b/src/HwmonTempSensor.cpp
index 09fb33f..6577739 100644
--- a/src/HwmonTempSensor.cpp
+++ b/src/HwmonTempSensor.cpp
@@ -52,11 +52,20 @@
            false, thisSensorParameters.maxValue, thisSensorParameters.minValue,
            conn, powerState),
     std::enable_shared_from_this<HwmonTempSensor>(), objServer(objectServer),
-    inputDev(io, open(path.c_str(), O_RDONLY)), waitTimer(io), path(path),
+    inputDev(io), waitTimer(io), path(path),
     offsetValue(thisSensorParameters.offsetValue),
     scaleValue(thisSensorParameters.scaleValue),
     sensorPollMs(static_cast<unsigned int>(pollRate * 1000))
 {
+    // NOLINTNEXTLINE(cppcoreguidelines-pro-type-vararg)
+    int fd = open(path.c_str(), O_RDONLY);
+    if (fd < 0)
+    {
+        std::cerr << "HwmonTempSensor " << sensorName << " failed to open "
+                  << path << "\n";
+    }
+    inputDev.assign(fd);
+
     sensorInterface = objectServer.add_interface(
         "/xyz/openbmc_project/sensors/" + thisSensorParameters.typeName + "/" +
             name,
@@ -164,6 +173,8 @@
 
     responseStream.clear();
     inputDev.close();
+
+    // NOLINTNEXTLINE(cppcoreguidelines-pro-type-vararg)
     int fd = open(path.c_str(), O_RDONLY);
     if (fd < 0)
     {
diff --git a/src/MCUTempSensor.cpp b/src/MCUTempSensor.cpp
index ede2a5e..4653bc8 100644
--- a/src/MCUTempSensor.cpp
+++ b/src/MCUTempSensor.cpp
@@ -102,8 +102,9 @@
 int MCUTempSensor::getMCURegsInfoWord(uint8_t regs, int16_t* pu16data)
 {
     std::string i2cBus = "/dev/i2c-" + std::to_string(busId);
-    int fd = open(i2cBus.c_str(), O_RDWR);
 
+    // NOLINTNEXTLINE(cppcoreguidelines-pro-type-vararg)
+    int fd = open(i2cBus.c_str(), O_RDWR);
     if (fd < 0)
     {
         std::cerr << " unable to open i2c device" << i2cBus << "  err=" << fd
@@ -111,6 +112,7 @@
         return -1;
     }
 
+    // NOLINTNEXTLINE(cppcoreguidelines-pro-type-vararg)
     if (ioctl(fd, I2C_SLAVE_FORCE, mcuAddress) < 0)
     {
         std::cerr << " unable to set device address\n";
@@ -119,6 +121,7 @@
     }
 
     unsigned long funcs = 0;
+    // NOLINTNEXTLINE(cppcoreguidelines-pro-type-vararg)
     if (ioctl(fd, I2C_FUNCS, &funcs) < 0)
     {
         std::cerr << " not support I2C_FUNCS\n";
diff --git a/src/NVMeBasicContext.cpp b/src/NVMeBasicContext.cpp
index ea17c73..0e04b16 100644
--- a/src/NVMeBasicContext.cpp
+++ b/src/NVMeBasicContext.cpp
@@ -61,26 +61,21 @@
 static ssize_t execBasicQuery(int bus, uint8_t addr, uint8_t cmd,
                               std::vector<uint8_t>& resp)
 {
-    std::array<char, PATH_MAX> devpath{};
+    int rc = 0;
     int32_t size = 0;
+    std::string devpath = "/dev/i2c-" + std::to_string(bus);
 
-    ssize_t rc =
-        snprintf(devpath.data(), devpath.size(), "/dev/i2c-%" PRIu32, bus);
-    if ((size_t)rc > sizeof(devpath))
-    {
-        std::cerr << "Failed to format device path for bus " << bus << "\n";
-        return -EINVAL;
-    }
-
-    int dev = ::open(devpath.data(), O_RDWR);
+    // NOLINTNEXTLINE(cppcoreguidelines-pro-type-vararg)
+    int dev = ::open(devpath.c_str(), O_RDWR);
     if (dev == -1)
     {
-        std::cerr << "Failed to open bus device " << devpath.data() << ": "
+        std::cerr << "Failed to open bus device " << devpath << ": "
                   << strerror(errno) << "\n";
         return -errno;
     }
 
     /* Select the target device */
+    // NOLINTNEXTLINE(cppcoreguidelines-pro-type-vararg)
     if (::ioctl(dev, I2C_SLAVE, addr) == -1)
     {
         rc = -errno;
diff --git a/src/PSUEvent.cpp b/src/PSUEvent.cpp
index 44275a3..7813741 100644
--- a/src/PSUEvent.cpp
+++ b/src/PSUEvent.cpp
@@ -157,6 +157,8 @@
     {
         eventPollMs = static_cast<unsigned int>(pollRate * 1000);
     }
+
+    // NOLINTNEXTLINE(cppcoreguidelines-pro-type-vararg)
     fd = open(path.c_str(), O_RDONLY);
     if (fd < 0)
     {
diff --git a/src/PSUSensor.cpp b/src/PSUSensor.cpp
index 99845b5..bbc0d2f 100644
--- a/src/PSUSensor.cpp
+++ b/src/PSUSensor.cpp
@@ -65,6 +65,7 @@
         sensorPollMs = static_cast<unsigned int>(pollRate * 1000);
     }
 
+    // NOLINTNEXTLINE(cppcoreguidelines-pro-type-vararg)
     fd = open(path.c_str(), O_RDONLY | O_NONBLOCK);
     if (fd < 0)
     {
diff --git a/src/TachSensor.cpp b/src/TachSensor.cpp
index d0051a0..f609410 100644
--- a/src/TachSensor.cpp
+++ b/src/TachSensor.cpp
@@ -53,10 +53,17 @@
            objectType, false, false, limits.second, limits.first, conn,
            powerState),
     objServer(objectServer), redundancy(redundancy),
-    presence(std::move(presenceSensor)),
-    inputDev(io, open(path.c_str(), O_RDONLY)), waitTimer(io), path(path),
-    led(ledIn)
+    presence(std::move(presenceSensor)), inputDev(io), waitTimer(io),
+    path(path), led(ledIn)
 {
+    // NOLINTNEXTLINE(cppcoreguidelines-pro-type-vararg)
+    int fd = open(path.c_str(), O_RDONLY);
+    if (fd < 0)
+    {
+        std::cerr << "Tach sensor failed to open file\n";
+    }
+    inputDev.assign(fd);
+
     sensorInterface = objectServer.add_interface(
         "/xyz/openbmc_project/sensors/fan_tach/" + name,
         "xyz.openbmc_project.Sensor.Value");
@@ -162,6 +169,8 @@
     }
     responseStream.clear();
     inputDev.close();
+
+    // NOLINTNEXTLINE(cppcoreguidelines-pro-type-vararg)
     int fd = open(path.c_str(), O_RDONLY);
     if (fd < 0)
     {
diff --git a/tests/test_Utils.cpp b/tests/test_Utils.cpp
index 63fcde8..a66b70c 100644
--- a/tests/test_Utils.cpp
+++ b/tests/test_Utils.cpp
@@ -65,7 +65,7 @@
              p != fs::recursive_directory_iterator(); ++p)
         {
             std::string path = p->path().string();
-            fprintf(stderr, "%s\n", path.c_str());
+            std::cerr << path << "\n";
             if (p.depth() >= 6)
             {
                 p.disable_recursion_pending();