%Error: t/t_flag_errorlimit_bad.v:10:8: Duplicate declaration of signal: 'u1'
   int u1;
       ^~
        t/t_flag_errorlimit_bad.v:9:8: ... Location of original declaration
   int u1;
       ^~
%Error: t/t_flag_errorlimit_bad.v:11:8: Duplicate declaration of signal: 'u1'
   int u1;
       ^~
        t/t_flag_errorlimit_bad.v:9:8: ... Location of original declaration
   int u1;
       ^~
%Error: Exiting due to