+
Alternatively, if the variable is set to an absolute path
(starting with a '/' character), Git will interpret this
-as a file path and will try to write the trace messages
-into it.
+as a file path and will try to append the trace messages
+to it.
+
Unsetting the variable, or setting it to empty, "0" or
"false" (case insensitive) disables trace messages.