MSBuild UsingTask Resolve References - msbuild

Question

I feel like I've fixed this before, but I can't remember how.
I have a tasks file that looks like this (CustomTasks.tasks):
<UsingTask AssemblyFile="CustomTasks.dll" TaskName="MyCustomTask"/>
it references an assembly (namely Ionic.Zip.dll). Ionic.Zip.dll is not in the GAC (and I don't want it to be). It sits right next to my CustomTasks.dll.
I have a directory called MSBuild one level up from my sln file which has CustomTasks.tasks, CustomTasks.dll and Ionic.Zip.dll in it.
I have a csproj that references the tasks file and calls the custom task:
<Import Project="$(ProjectDir)\..\MSBuild\CustomTasks.tasks" />
<MyCustomTask ..... />
at build time, this yields:
The "MyCustomTask" task could not be loaded from the assembly ....MyCustomTasks.dll. Could not load file or assembly 'Ionic.Zip,......' or one of its dependencies.

Answer 1

Got tired and frustrated and took a direct approach...I don't think this is the same way I solved the problem previously...but maybe this will help someone else. Other, more elegant solutions are more than welcome.
<Target Name="BeforeBeforeBuild" BeforeTargets="BeforeBuild">
<HandleAssemblyResolve SearchPath="$(ProjectDir)\..\MSBuild\" />
</Target>
<UsingTask TaskName="HandleAssemblyResolve" TaskFactory="CodeTaskFactory" AssemblyFile="$(MSBuildToolsPath)\Microsoft.Build.Tasks.v4.0.dll">
<ParameterGroup>
<SearchPath ParameterType="System.String" Required="true" />
</ParameterGroup>
<Task>
<Using Namespace="System" />
<Using Namespace="System.IO" />
<Using Namespace="System.Reflection" />
<Code Type="Fragment" Language="cs">
<![CDATA[
AppDomain.CurrentDomain.AssemblyResolve += (sender, e) =>
{
var assemblySearchPath = Path.Combine(SearchPath, e.Name.Split(',')[0]);
if (File.Exists(assemblySearchPath)) return Assembly.LoadFrom(assemblySearchPath);
return null;
};
]]>
</Code>
</Task>
</UsingTask>

Answer 2

This is actually easy to fix. Put your custom build tasks and dependencies in a different folder. Then dependencies are loaded correctly.
For example like so:
<UsingTask AssemblyFile="..\BuildTools\CustomTasks.dll" TaskName="MyCustomTask"/>