/usr/include/GNUstep/GDLAccess/ is in libsope-dev 2.2.9-2.
This file is owned by root:root, with mode 0o755.
..
/usr/include/GNUstep/GDLAccess/EOAdaptor.h
/usr/include/GNUstep/GDLAccess/EOAdaptorChannel+Attributes.h
/usr/include/GNUstep/GDLAccess/EOAdaptorChannel.h
/usr/include/GNUstep/GDLAccess/EOAdaptorContext.h
/usr/include/GNUstep/GDLAccess/EOAdaptorDataSource.h
/usr/include/GNUstep/GDLAccess/EOAdaptorGlobalID.h
/usr/include/GNUstep/GDLAccess/EOAdaptorOperation.h
/usr/include/GNUstep/GDLAccess/EOArrayProxy.h
/usr/include/GNUstep/GDLAccess/EOAttribute.h
/usr/include/GNUstep/GDLAccess/EOAttributeOrdering.h
/usr/include/GNUstep/GDLAccess/EOCustomValues.h
/usr/include/GNUstep/GDLAccess/EODatabase.h
/usr/include/GNUstep/GDLAccess/EODatabaseChannel.h
/usr/include/GNUstep/GDLAccess/EODatabaseContext.h
/usr/include/GNUstep/GDLAccess/EODatabaseFault.h
/usr/include/GNUstep/GDLAccess/EODatabaseFaultResolver.h
/usr/include/GNUstep/GDLAccess/EODelegateResponse.h
/usr/include/GNUstep/GDLAccess/EOEntity+Factory.h
/usr/include/GNUstep/GDLAccess/EOEntity.h
/usr/include/GNUstep/GDLAccess/EOExpressionArray.h
/usr/include/GNUstep/GDLAccess/EOFExceptions.h
/usr/include/GNUstep/GDLAccess/EOFault.h
/usr/include/GNUstep/GDLAccess/EOFaultHandler.h
/usr/include/GNUstep/GDLAccess/EOGenericRecord.h
/usr/include/GNUstep/GDLAccess/EOJoinTypes.h
/usr/include/GNUstep/GDLAccess/EOKeySortOrdering.h
/usr/include/GNUstep/GDLAccess/EOModel.h
/usr/include/GNUstep/GDLAccess/EOModelGroup.h
/usr/include/GNUstep/GDLAccess/EONull.h
/usr/include/GNUstep/GDLAccess/EOObjectUniquer.h
/usr/include/GNUstep/GDLAccess/EOPrimaryKeyDictionary.h
/usr/include/GNUstep/GDLAccess/EOQuotedExpression.h
/usr/include/GNUstep/GDLAccess/EORecordDictionary.h
/usr/include/GNUstep/GDLAccess/EORelationship.h
/usr/include/GNUstep/GDLAccess/EOSQLExpression.h
/usr/include/GNUstep/GDLAccess/EOSQLQualifier.h
/usr/include/GNUstep/GDLAccess/GDLAccess.h
/usr/include/GNUstep/GDLAccess/NSObject+EONullInit.h