Failing test for FluentAssertions (tested with 4.1.1, but seen in earlier versions as well). When explicitly using Including(), another property with a similar name is also matched, and the match subsequently fails.

FluentAssertionsShouldBeEquivalentToTest.cs

using FluentAssertions;
using Xunit;

// ReSharper disable InconsistentNaming

namespace FluentAssertionsBugProof
{
	public class ShouldBeEquivalentToTest
	{
		[Fact]
		public void ShouldBeEquivalent_NoInheritance_SimilarPropertyNames_DoesNotThrow()
		{
			var x = new TestNoInheritance
			        {
				        DeclaredType = LocalOtherType.NonDefault,
				        Type = LocalType.NonDefault,
			        };

			x.ShouldBeEquivalentTo(new TestNoInheritance
			                       {
				                       DeclaredType = LocalOtherType.NonDefault,
			                       },
			                       config => config.Including(o => o.DeclaredType));
		}

		[Fact]
		public void ShouldBeEquivalent_NoInheritance_DifferentPropertyNames_DoesNotThrow()
		{
			var x = new TestNoInheritanceDifferentNames
			        {
				        DeclaredType = LocalOtherType.NonDefault,
				        InheritedType = LocalType.NonDefault,
			        };

			x.ShouldBeEquivalentTo(new TestNoInheritanceDifferentNames
			                       {
				                       DeclaredType = LocalOtherType.NonDefault,
			                       },
			                       config => config.Including(o => o.DeclaredType));
		}
	}

	public class TestNoInheritance
	{
		public LocalType Type { get; set; }
		public LocalOtherType DeclaredType { get; set; }
	}

	public class TestNoInheritanceDifferentNames
	{
		public LocalType InheritedType { get; set; }
		public LocalOtherType DeclaredType { get; set; }
	}

	public enum LocalOtherType: byte
	{
		Default,
		NonDefault,
	}

	public enum LocalType: byte
	{
		Default,
		NonDefault,
	}
}