+This variable should contain a comma separated list of debugging options.
+Currently, the following options are supported:
+.RS
+.ne 8
+.TP
+.I "collect-pagefault-stats"
+Collects information about pagefaults. This is used internally to
+track the number of page faults produced to load metadata. To display
+this information you must use this option with "--stats" command line option.
+.TP
+.I "handle-sigint"
+Captures the interrupt signal (Control-C) and displays a stack trace
+when pressed. Useful to find out where the program is executing at a
+given point. This only displays the stack trace of a single thread.
+.TP
+.I "keep-delegates"
+This option will leak delegate trampolines that are no longer
+referenced as to present the user with more information about a
+delegate missuse. Basically a delegate instance might be created,
+passed to unmanaged code, and no references kept in managed code,
+which will garbage collect the code. With this option it is possible
+to track down the source of the problems.
+.ne
+.RE
+.TP
+.I "MONO_DISABLE_AIO"
+If set, tells mono NOT to attempt using native asynchronous I/O services. In
+that case, a default select/poll implementation is used. Currently only epoll()
+is supported.
+.TP
+.I "MONO_EGD_SOCKET"
+For platforms that do not otherwise have a way of obtaining random bytes
+this can be set to the name of a file system socket on which an egd or
+prngd daemon is listening.
+.TP
+.I "MONO_EXTERNAL_ENCODINGS"
+If set, contains a colon-separated list of text encodings to try when
+turning externally-generated text (e.g. command-line arguments or
+filenames) into Unicode. The encoding names come from the list
+provided by iconv, and the special case "default_locale" which refers
+to the current locale's default encoding.
+.IP
+When reading externally-generated text strings UTF-8 is tried first,
+and then this list is tried in order with the first successful
+conversion ending the search. When writing external text (e.g. new
+filenames or arguments to new processes) the first item in this list
+is used, or UTF-8 if the environment variable is not set.
+.TP
+.I "MONO_GAC_PREFIX"
+Provides a prefix the runtime uses to look for Global Assembly Caches.
+Directories are separated by the platform path separator (colons on
+unix). MONO_GAC_PREFIX should point to the top directory of a prefixed
+install. Or to the directory provided in the gacutil /gacdir command. Example:
+.B /home/username/.mono:/usr/local/mono/
+.TP
+.I "MONO_LOG_LEVEL"
+The logging level, possible values are `error', `critical', `warning',
+`message', `info' and `debug'. See the DEBUGGING section for more
+details.
+.TP
+.I "MONO_LOG_MASK"
+Controls the domain of the Mono runtime that logging will apply to.
+If set, the log mask is changed to the set value. Possible values are
+"asm" (assembly loader), "type", "dll" (native library loader), "gc"
+(garbage collector), "cfg" (config file loader), "aot" (precompiler) and "all".
+The default value is "all". Changing the mask value allows you to display only
+messages for a certain component. You can use multiple masks by comma
+separating them. For example to see config file messages and assembly loader
+messages set you mask to "asm,cfg".
+.TP
+.I "MONO_MANAGED_WATCHER"
+If set to any value, System.IO.FileSystemWatcher will use the default
+managed implementation (slow). If unset, mono will try to use FAM under
+Unix systems and native API calls on Windows, falling back to the
+managed implementation on error.
+.TP
+.I "MONO_PATH"
+Provides a search path to the runtime where to look for library files.
+Directories are separated by the platform path separator (colons on unix). Example:
+.B /home/username/lib:/usr/local/mono/lib
+.TP
+.I "MONO_RTC"
+Experimental RTC support in the statistical profiler: if the user has
+the permission, more accurate statistics are gathered. The MONO_RTC
+value must be restricted to what the linux rtc allows: power of two
+from 64 to 8192 Hz. To enable higher frequencies like 4096 Hz, run as root:
+.nf
+
+ echo 4096 > /proc/sys/dev/rtc/max-user-freq
+
+.fi
+.Sp
+For example:
+.nf