core data - "_Unwind_Resume" called upon dead simple fetch request -

i'm trying port on core data code on test mac os application iphone app. set helper method manage of code fetches, , works great on mac os, error on iphone:

detected attempt call symbol in system libraries not present on iphone: _unwind_resume called function -[nssqladapter _newselectstatementwithfetchrequest:ignoreinheritance:] in image coredata. 

here code calls helper method:

// authors , title works      nsarray *bookinfofetchresults = [self getentitiesbyname:koc_cd_objectkey_bookinfo                                          usingpredicatevalue:@"contentroot.bookinfo.bookauthors > \"\""                                    withsubstitutionvariables:[nsdictionary dictionarywithobjectsandkeys:nil]                                                      inmodel:model                                                   andcontext:context                                             sortbyattribute:nil];     int thisresult = 0;     int lastresult = [bookinfofetchresults count];     (thisresult = 0; thisresult < lastresult; thisresult++) {         nsmanagedobject *currentresult = [bookinfofetchresults objectatindex:thisresult];         nslog(@"bookauthors: %@", [currentresult valueforkey:koc_cd_objectattribute_bookauthors]);         nslog(@"booktitle: %@", [currentresult valueforkey:koc_cd_objectattribute_booktitle]);     }      // chapters not work      nsarray *chapterfetchresults = [self getentitiesbyname:koc_cd_objectkey_chapter                                        usingpredicatevalue:@"all contentroot.chapters.title > \"\""                                   withsubstitutionvariables:[nsdictionary dictionarywithobjectsandkeys:nil]                                                     inmodel:model                                                  andcontext:context                                             sortbyattribute:koc_cd_objectattribute_key];      int thischapterresult = 0;     int lastchapterresult = [chapterfetchresults count];     (thischapterresult = 0; thischapterresult < lastchapterresult; thischapterresult++) {         nsmanagedobject *currentchapterresult = [chapterfetchresults objectatindex:thischapterresult];         nslog(@"chapter %@: %@", [currentchapterresult valueforkey:koc_cd_objectattribute_number], [currentchapterresult valueforkey:koc_cd_objectattribute_title]);     } 

the helper method (stripped of error-checking, though removing didn't change resulting error):

- (nsarray *) getentitiesbyname:(nsstring *)entityname usingpredicatevalue:(nsstring *)predicatevalue withsubstitutionvariables:(nsdictionary *)variablesdict inmodel:(nsmanagedobjectmodel *)amodel andcontext:(nsmanagedobjectcontext *)acontext sortbyattribute:(nsstring *)sortingattribute; {     nsarray *fetchresults;          nsstring *fetchrequesttemplatename = [nsstring stringwithformat:@"get_%@", entityname];          nsfetchrequest *fetchrequesttemplate = [[nsfetchrequest alloc] init];         nsentitydescription *targetentitydescription;         targetentitydescription = [[amodel entitiesbyname] objectforkey:entityname];         [fetchrequesttemplate setentity:targetentitydescription];          // need find way catch error here in case give isn't right         // nsinvalidargumentexception: unable parse format string "mqaynh5bxs"         nspredicate *predicatetemplate = [nspredicate predicatewithformat:predicatevalue];          [fetchrequesttemplate setpredicate:predicatetemplate];         [amodel setfetchrequesttemplate:fetchrequesttemplate forname:fetchrequesttemplatename];         [fetchrequesttemplate release];          if (variablesdict == nil) {             variablesdict = [nsdictionary dictionarywithobjectsandkeys:nil];             [variablesdict retain];         }          nsfetchrequest *fetchrequesttoexecute = [amodel fetchrequestfromtemplatewithname:fetchrequesttemplatename substitutionvariables:variablesdict];          nserror *fetcherror;         fetchresults = [acontext executefetchrequest:fetchrequesttoexecute error:&fetcherror];       if ((sortingattribute != nil) && (fetchresults != nil)) {         nssortdescriptor *attributesorter = [[nssortdescriptor alloc] initwithkey:sortingattribute ascending:yes];         fetchresults = [fetchresults sortedarrayusingdescriptors:[nsarray arraywithobject:attributesorter]];         [attributesorter release];     }      return fetchresults;  } 

the point of failure in helper method is:

fetchresults = [acontext executefetchrequest:fetchrequesttoexecute error:&fetcherror]; 

breaking out code helper method doesn't work either.

i don't know if help, after stripping out error-handling code in helper method, this:

2010-11-30 16:31:30.633 oc flash card core 2[19306:207] *** terminating app due uncaught exception 'nsinvalidargumentexception', reason: 'unsupported predicate (null)' *** call stack @ first throw: (     0   corefoundation                      0x02655b99 __exceptionpreprocess + 185     1   libobjc.a.dylib                     0x027a540e objc_exception_throw + 47     2   coredata                            0x02381e86 -[nssqlgenerator generatesqlstatementforfetchrequest:ignoreinheritance:countonly:] + 1254     3   coredata                            0x023816f0 -[nssqladapter _newselectstatementwithfetchrequest:ignoreinheritance:] + 480     4   coredata                            0x02381501 -[nssqladapter newselectstatementwithfetchrequest:] + 49     5   coredata                            0x023813ae -[nssqlcore newrowsforfetchplan:] + 430     6   coredata                            0x02380b09 -[nssqlcore objectsforfetchrequest:incontext:] + 297     7   coredata                            0x023806fe -[nssqlcore executerequest:withcontext:error:] + 206     8   coredata                            0x0242e91c -[nspersistentstorecoordinator executerequest:withcontext:error:] + 1084     9   coredata                            0x0237d897 -[nsmanagedobjectcontext executefetchrequest:error:] + 359     10  oc flash card core 2                0x0000360e -[occontentimporterobj getentitiesbyname:usingpredicatevalue:withsubstitutionvariables:inmodel:andcontext:sortbyattribute:] + 481     11  oc flash card core 2                0x00002af7 -[occontentimporterobj testcoredataintegrity] + 188     12  oc flash card core 2                0x00002864 -[occontentimporterobj importcontent] + 88     13  oc flash card core 2                0x0000252b -[appdelegate_iphone application:didfinishlaunchingwithoptions:] + 91     14  uikit                               0x002b4f27 -[uiapplication _callinitializationdelegatesforurl:payload:suspended:] + 1163     15  uikit                               0x002b73b0 -[uiapplication _runwithurl:payload:launchorientation:statusbarstyle:statusbarhidden:] + 346     16  uikit                               0x002c13ec -[uiapplication handleevent:withnewevent:] + 1958     17  uikit                               0x002b9b3c -[uiapplication sendevent:] + 71     18  uikit                               0x002be9bf _uiapplicationhandleevent + 7672     19  graphicsservices                    0x02f35822 purpleeventcallback + 1550     20  corefoundation                      0x02636ff4 __cfrunloop_is_calling_out_to_a_source1_perform_function__ + 52     21  corefoundation                      0x02597807 __cfrunloopdosource1 + 215     22  corefoundation                      0x02594a93 __cfrunlooprun + 979     23  corefoundation                      0x02594350 cfrunlooprunspecific + 208     24  corefoundation                      0x02594271 cfrunloopruninmode + 97     25  uikit                               0x002b6c6d -[uiapplication _run] + 625     26  uikit                               0x002c2af2 uiapplicationmain + 1160     27  oc flash card core 2                0x00001ce0 main + 102     28  oc flash card core 2                0x00001c71 start + 53 ) terminate called after throwing instance of 'nsexception' 

but, again, of worked flawlessly in mac os. i've tried searching _unwind_resume seems bug on apple's part, , there @ least dozen different ways hit , dozen different ways resolve it. differential can think of 1 attempt has 1 instance in cd store (intentionally so) , second, trouble one, can have many. ideas?

figured out how around this: in predicate used search, all keyword needs any.

what don't understand why case. error given seems obscure, , fact ends exc_bad_access troubling. i'm willing accept answer can explain why there such difference between any , all.