Update CONTRIBUTING.md

Author: vlad-perevezentsev

CONTRIBUTING.md

@@ -191,3 +191,43 @@ these steps:
 >    ```
 >    The error is related to the `tcl` package. You should uninstall the `tcl`
 > package to resolve the error.
+
+## Error Reporting and Logging
+
+Use the `DPCTL_VERBOSITY` environment variable to print errors of different severity levels from the libsyclinterface library to the console.
+You can specify one of the following severity levels (in increasing order of severity): `warning` and `error`.
+
+```bash
+export DPCTL_VERBOSITY=error
+```
+
+Messages of a given severity are shown not only in the console for that severity, but also for a lower severity. For example, the severity level `error` will output severity errors for `error` and `warning` to the console.
+
+### Optional use of the Google logging library (glog)
+
+Dpctl's error handler for libsyclinterface can be optionally configured to use [glog](https://github.com/google/glog). To use glog, follow the following steps:
+
+1. Install glog package of the latest version (0.5.0)
+
+```bash
+conda install glog
+```
+2. Build dpctl with glog support
+
+```bash
+python scripts/build_locally.py --oneapi --glog
+```
+
+3. Use `DPCTLService_InitLogger` and `DPCTLService_ShutdownLogger` functions during development to initialize the Google's logging library and de-initialize accordingly
+
+```bash
+DPCTLService_InitLogger(const char *app_name, const char *log_dir);
+DPCTLService_ShutdownLogger();
+```
+
+ - `*app_name` - name of the executable file (prefix for logs of various levels).
+ - `*log_dir` - directory path for writing log files.
+
+> **_NOTE:_**
+>
+> If `InitGoogleLogging` is not called before first use of glog, the library will self-initialize to `logtostderr` mode and log files will not be generated.