Why is there no value in GH0100?

At the last calc spec shown the debugger shows a value 
for QUSRTVUSP but no value for GH0100.  Why?

...
D* Retrieve from a user space.                                  
D QUSRTVUS        PR                  EXTPGM('QUSRTVUS')        
D  Spc_Lib                      20A   CONST                     
D  Start                        10i 0 CONST                     
D  Length                       10i 0 CONST                     
D  DataRead                  32765A   VARYING OPTIONS(*VARSIZE) 
D  qusrtvusEr                         LIKE(ERRC0100)            
...
D QUSRTVUSP       S          32765A    VARYING
...
 * List API - Generic Header Format 0100 from 'System API Reference'
D GH0100          DS                                                
D  GHUser                       64A                                 
D  GHGHSize                     10i 0                               
D  GHRelease                     4A                                 
D  GHFormat                      8A                                 
...
D GH0100P         S                    LIKE(GH0100)
...
C                   CALLP     QUSRTVUS('JOBLIST   QTEMP     ':   
C                                       1:%len(GH0100P):QUSRTVUSP
C                                       ERRC0100P)               
C                   eval      errc0100=errc0100p                 
C                   if        exceptionId<>*blanks               
C                   return                                       
C                   endif                                        
C                   eval      GH0100=QUSRTVUSP                   
                                                                 
 * Initialize our offset to the offset of the list data.         
C                   eval      CurOffSet=GHListOff                

EVAL QUSRTVUSP :X                                                    
   00000     00000000 00000000 00000000 00000000   - ................
   00010     00000000 00000000 00000000 00000000   - ................
   00020     00000000 00000000 00000000 00000000   - ................
   00030     00000000 00000000 00000000 00000000   - ................
   00040     00000080 F0F1F0F0 D1D6C2D3 F0F1F0F0   - ...Ø0100JOBL0100
   00050     D8E4E2D3 D1D6C240 4040F1F0 F0F0F2F0   - QUSLJOB   100020
   00060     F2F0F9F4 F9F4F1C3 00000228 000000C0   - 2094941C.......{
...
EVAL GH0100 :X                                                            
   00000     40404040 40404040 40404040 40404040   -                      
   00010     40404040 40404040 40404040 40404040   -                      
   00020     40404040 40404040 40404040 40404040   -                      
   00030     40404040 40404040 40404040 40404040   -                      
   00040     40404040 40404040 40404040 40404040   -                      
   00050     40404040 40404040 40404040 40404040   -                      
   00060     40404040 40404040 40404040 40404040   -                      
   00070     40404040 40404040 40404040 40404040   -                      
   00080     40404040 40404040 40404040 40404040   -                      

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