[MonoDevelop] TextTransform.exe not finding referenced assemblies

[Tom Cook]

Sorry if this is the wrong forum for this.

I'm trying to port some T4 templates from Windows to Mono on Linux.
They include <#@ assembly #> references to an assembly which provides
some custom functions written in C# which are used in the templates.
Within the templates, these are given as:

    <#@ assembly name="DataModelDefinition.dll" #>

The assembly builds fine in Monodevelop using the pre-existing Visual
Studio 2013 solution, but no matter what I try, I can't make
TextTransform find this assembly.  So far I've tried adding an
explicit reference to the assembly on the command line:

    TextTransform.exe
-r=$(pwd)Output/x86/Release/DataModelDefinition.dll ...
ProcessFiles.tt

and telling TextTransform where to search for it:

    TextTransform.exe -P=$(pwd)Output/x86/Release ... ProcessFiles.tt

and setting MONO_PATH to find it:

    export MONO_PATH=$(pwd)Output/x86/Release
    TextTransform.exe ... ProcessFiles.tt

as well as various combinations of the above, but no matter what I try
the answer is always the same:

    Processing 'ProcessFiles.tt'... failed.
    (0,0): ERROR Metadata file `GH.DataModelDefinition.dll' could not be found

Is there some way to get TextTransform to find this file?

Thanks,
Tom