ODB Relationship fails to compile

I have a very simple relationship setup which I cannot get the odb output to compile and it's giving me the below compiler error. I am using Qt smart pointers to implement the relationship and I always seem to be running into the same error no matter how many permutations I go through.

/usr/local/include/odb/database.ixx:570:54: error: no matching function for call to ‘odb::object_traits_impl<Inspection, (odb::database_id)1u>::find(odb::database&, const id_type&)’

here is the the parent class

#ifndef PART_H
#define PART_H

class Part;

#include <odb/core.hxx>
#include <odb/qt/lazy-ptr.hxx>
#include <QtCore/QString>
#include <QtCore/QByteArray>
#include <QtCore/QUuid>
#include <QtCore/QDateTime>
#include <QtCore/QSharedPointer>
#include <QtCore/QList>
#include <QtCore/QSet>
#include "Inspection.h"

/** this class represents the atomic parts which are acquired */
#pragma db object
class Part{
public:

    /** public constructor */
    Part(QString id);

    /** gets the id */
    const QString Id() const;

    /** Get (or create) the inspection for a given system name */
    QSharedPointer<Inspection> GetInspection(QString systemName = "");

private:

    /** constructor */
    Part(){}

    /** odb needed reference */
    friend class odb::access;

    /** a list of all of the inspections for this part */
    //#pragma db value_not_null inverse(parent)
    QList<QSharedPointer<Inspection> > inspections;

    /** holds a unique name/id for this object */
    #pragma db id
    QString id;
};

#endif // PART_H

And here is the child

#ifndef INSPECTION_H
#define INSPECTION_H

class Inspection;

#include <odb/core.hxx>
#include <odb/qt/lazy-ptr.hxx>
#include <QtCore/QString>
#include <QtCore/QByteArray>
#include <QtCore/QUuid>
#include <QtCore/QDateTime>
#include <QtCore/QSharedPointer>
#include <QtCore/QList>
#include <QtCore/QSet>
//#include "SurfaceDefect.h"
#include "vec2f.h"
#include "Part.h"
#include "MILImage.h"

using namespace std;

#pragma db object
class Inspection{
public:

    /** gets the full image object for this inspection */
    const QWeakPointer<MILImage> GetFullImage() const;

    /** gets the start time of the inspection */
    const QDateTime GetStarted() const;

    /** gets the end time of the inspection */
    const QDateTime GetEnded() const;

    /** Gets the system name on which the inspection was acquired */
    const QString GetSystemName() const;

    /** sets the full image and takes ownership of it */
    void SetFullImage(MILImage* fullImage);

    /** sets the start time of the inspection */
    void SetStarted(QDateTime started);

    /** Sets the end time of the inspection */
    void SetEnded(QDateTime ended);

private:

    /** constructor */
    Inspection(QString systemName);

    /** odb needed reference */
    friend class odb::access;

    /** we give access to the part class to allow for construction */
    friend class Part;

    /** A unique identifier for the inspection */
    #pragma db id
    QUuid id;

    /** the name of the system which acquired the inspection */
    QString systemName;

    /** The time and date the inspection was recorded to disk */
    QDateTime Recorded;

    /** A vector of all defects */
    //#pragma db inverse(Source)
    //QVector< QLazyWeakPointer<SurfaceDefect> > SurfaceDefects;

    /** The username of the person inspecting the sheet */
    QString Username;

    /** All the metadata crammed into one QString */
    QString MetaData;

    /** The positions of the 4 corners of a sheet */
    // TODO: this should not be transient
    #pragma db transient
    Vec2f Corners[4];

    /** The time and date the inspection started */
    QDateTime started;

    /** the time and date the inspection ended */
    QDateTime ended;

    /** the full inspection image */
    #pragma db transient
    QSharedPointer<MILImage> fullImage;

    /** the parent part of this object */
    #pragma db not_null
    QSharedPointer<Part> parent;
};

#endif // INSPECTION_H

Any help which could be given would be great!

I was able to get feedback from an ODB developer who stated that this can happen when one fails to create an default constructor as I did in the Inspection class. Thanks Boris!