What causes: Unix transport error? - nhibernate

Question

I'm doing unit test(using NUnit) on Postgresql, unfortunately it causes an error:
Internal error
RemotingException: Unix transport error.
Note: The error doesn't happen if I'm using Sqlite
Code:
using System;
using ncfg = NHibernate.Cfg;
using System.Collections.Generic;
using System.Reflection;
using NHibernate;
using System.Data;
using NHibernate.Tool.hbm2ddl;
using NHibernate.Dialect;
using NHibernate.Driver;
using NHibernate.ByteCode.LinFu;
using NUnit.Framework;
using NHibernate.Mapping;
namespace RuntimeNhibernate
{
class MainClass
{
public static void Main (string[] args)
{
using(var c = new BlogTestFixture())
{
c.CanSaveAndLoadBlog();
}
}
}
public class InMemoryDatabaseTest : IDisposable
{
private static ncfg.Configuration Configuration;
private static ISessionFactory SessionFactory;
protected ISession session;
public InMemoryDatabaseTest(Assembly assemblyContainingMapping)
{
if (Configuration == null)
{
Configuration = new ncfg.Configuration()
.SetProperty(ncfg.Environment.ReleaseConnections,"on_close")
.SetProperty(ncfg.Environment.Dialect, typeof (SQLiteDialect).AssemblyQualifiedName)
.SetProperty(ncfg.Environment.ConnectionDriver, typeof(SQLite20Driver).AssemblyQualifiedName)
.SetProperty(ncfg.Environment.ConnectionString, "data source=:memory:")
.SetProperty(ncfg.Environment.ProxyFactoryFactoryClass, typeof (ProxyFactoryFactory).AssemblyQualifiedName)
.AddAssembly(assemblyContainingMapping);
/*Configuration = new ncfg.Configuration()
.SetProperty(ncfg.Environment.ReleaseConnections,"on_close")
.SetProperty(ncfg.Environment.Dialect, typeof (PostgreSQLDialect).AssemblyQualifiedName)
.SetProperty(ncfg.Environment.ConnectionDriver, typeof(NpgsqlDriver).AssemblyQualifiedName)
.SetProperty(ncfg.Environment.ConnectionString, "Server=127.0.0.1;Database=memdb;User ID=postgres;Password=password;Pooling=false;")
.SetProperty(ncfg.Environment.ProxyFactoryFactoryClass, typeof (ProxyFactoryFactory).AssemblyQualifiedName)
.AddAssembly(assemblyContainingMapping);*/
SessionFactory = Configuration.BuildSessionFactory();
}
session = SessionFactory.OpenSession();
new SchemaExport(Configuration).Execute(true, true, false, session.Connection, Console.Out);
}
public void Dispose()
{
session.Dispose();
}
}//class InMemory
public class Blog
{
public virtual int BlogId { get; set; }
public virtual bool AllowsComments { set; get; }
public virtual DateTime CreatedAt { get; set; }
public virtual string Subtitle { get; set; }
public virtual string Title { get; set; }
}
[TestFixture]
public class BlogTestFixture : InMemoryDatabaseTest
{
public BlogTestFixture() : base(typeof(Blog).Assembly)
{
}
[Test]
public void IsOK()
{
Assert.AreEqual(true, true);
return;
}
[Test]
public void CanSaveAndLoadBlog()
{
object id;
using (var tx = session.BeginTransaction())
{
id = session.Save(new Blog
{
AllowsComments = true,
CreatedAt = new DateTime(2000,1,1),
Subtitle = "Hello",
Title = "World",
});
tx.Commit();
}
session.Clear();
Console.WriteLine("Hello {0}", id);
using (var tx = session.BeginTransaction())
{
var blog = session.Get<Blog>(id);
Assert.AreEqual(new DateTime(2000, 1, 1), blog.CreatedAt);
Assert.AreEqual("Hello", blog.Subtitle);
Assert.AreEqual("World", blog.Title);
Assert.AreEqual(true, blog.AllowsComments);
tx.Commit();
}
}
}//Test
}//namespace
What could be the possible reason when I unit test Postgresql, it results to RemotingException: Unix transport error. ?
If I run the code outside of unit test (e.g. Main), it works. Btw, if I unit test Sqlite, it doesn't cause any errors too

Answer 1

Found the answer, I tried launching MonoDevelop from Terminal (/Applications/MonoDevelop.app/Contents/MacOS/monodevelop), I saw the more detailed error from the commandline when I ran the unit tests.
Unhandled Exception: System.TypeInitializationException: An exception was thrown by the type initializer for Npgsql.NpgsqlConnection ---> System.TypeLoadException: Could not load type 'System.Runtime.Versioning.TargetFrameworkAttribute' from assembly 'Npgsql'.
at (wrapper managed-to-native) System.MonoCustomAttrs:GetCustomAttributesInternal (System.Reflection.ICustomAttributeProvider,System.Type,bool)
at System.MonoCustomAttrs.GetCustomAttributesBase (ICustomAttributeProvider obj, System.Type attributeType) [0x00000] in <filename unknown>:0
at System.MonoCustomAttrs.GetCustomAttributes (ICustomAttributeProvider obj, System.Type attributeType, Boolean inherit) [0x00000] in <filename unknown>:0
at System.Reflection.Assembly.GetCustomAttributes (System.Type attributeType, Boolean inherit) [0x00000] in <filename unknown>:0
at System.Resources.ResourceManager.GetNeutralResourcesLanguage (System.Reflection.Assembly a) [0x00000] in <filename unknown>:0
at System.Resources.ResourceManager..ctor (System.Type resourceSource) [0x00000] in <filename unknown>:0
at Npgsql.NpgsqlConnection..cctor () [0x00000] in <filename unknown>:0
--- End of inner exception stack trace ---
at (wrapper managed-to-native) System.Reflection.MonoCMethod:InternalInvoke (System.Reflection.MonoCMethod*,object,object[],System.Exception&)
at System.Reflection.MonoCMethod.Invoke (System.Object obj, BindingFlags invokeAttr, System.Reflection.Binder binder, System.Object[] parameters, System.Globalization.CultureInfo culture) [0x00000] in <filename unknown>:0
Then I tried changing the Npgsql version(the one that causes an error came from http://pgfoundry.org/frs/download.php/2868/Npgsql2.0.11-bin-ms.net4.0.zip) to http://pgfoundry.org/frs/download.php/2860/Npgsql2.0.11-bin-mono2.0.zip After this, there's no more Unix transport error ^_^
Lesson learned, use the Mono version of the component you are using if you are running things on Mono

Answer 2

This exception occurs, when a unit test in MonoDevelop raises an exception, which could not be caught by the test runner (i.e. when the test starts some threads and they crash).
If you have such a test which is grey even after running
and the unit test pad shows the internal error
you should try running the test on your console with nunit-console (should be in the repo of your distro where mono comes from) and leak the exception.
In my case it was a simple multiple enumeration exception in a sub-thread of my test.
Unhandled exceptions:
1) Residata.Platform.Server.Message.Test.MemoryBrokerTest.AssertThatReceiveMethodWaitsUntilPublish : System.InvalidOperationException: Collection was modified; enumeration operation may not execute.
at System.Collections.Generic.List`1+Enumerator[Residata.Platform.Contract.Message.IPackage].MoveNext () [0x00000] in <filename unknown>:0