NOTDIR "not a directory"
STAT "stat error"
UNLINK "failed to unlink file"
+WRITE "write error"
+OPEN "failed to open file"
+TRUNCATE "could not truncate file"
+MKDIR "failed to create directory"
+RENAME "could not rename file"
+MUNMAP "munmap error"
+FSTAT "fstat error"
+DIR_EXISTS "directory exists"
+NOENT "no such file"