docs/users_guide/phases.xml:592: parser error : Opening and ending tag mismatch: option line 592 and code
          <option>-fno-code</code>, which normally suppresses generation
                                  ^
docs/users_guide/phases.xml:1243: parser error : chunk is not well balanced

^
docs/users_guide/using.xml:2735: parser error : Failure to process entity phases
  &phases;
          ^
docs/users_guide/using.xml:2735: parser error : Entity 'phases' not defined
  &phases;
          ^
docs/users_guide/using.xml:3042: parser error : chunk is not well balanced

^
docs/users_guide/ug-book.xml:14: parser error : Failure to process entity using
&using;
       ^
docs/users_guide/ug-book.xml:14: parser error : Entity 'using' not defined
&using;
       ^
docs/users_guide/users_guide.xml:10: parser error : Failure to process entity ug-book
&ug-book;
         ^
docs/users_guide/users_guide.xml:10: parser error : Entity 'ug-book' not defined
&ug-book;
         ^
unable to parse docs/users_guide/users_guide.xml
gmake[1]: *** [docs/users_guide/users_guide/index.html] Error 6
gmake: *** [all] Error 2