Output of nant is:

Buildfile: file:///root/opensim-0.6.8-release/OpenSim.build
Target framework: Mono 2.0 Profile
Target(s) specified: build 

     [echo] Using 'mono-2.0' Framework

init:


Debug:

     [echo] Platform unix

build:

     [nant] /root/opensim-0.6.8-release/OpenSim/Framework/Servers/HttpServer/OpenSim.Framework.Servers.HttpServer.dll.build build
            Buildfile: file:///root/opensim-0.6.8-release/OpenSim/Framework/Servers/HttpServer/OpenSim.Framework.Servers.HttpServer.dll.build
            Target framework: Mono 2.0 Profile
            Target(s) specified: build 


            build:

                 [echo] Build Directory is /root/opensim-0.6.8-release/OpenSim/Framework/Servers/HttpServer/bin/Debug
                  [csc] Compiling 29 files to '/root/opensim-0.6.8-release/OpenSim/Framework/Servers/HttpServer/bin/Debug/OpenSim.Framework.Servers.HttpServer.dll'.
                  [csc] /root/opensim-0.6.8-release/OpenSim/Framework/Servers/HttpServer/AsynchronousRestObjectRequester.cs(103,41): error CS0246: The type or namespace name `TResponse' could not be found. Are you missing a using directive or an assembly reference?
                  [csc] Compilation failed: 1 error(s), 0 warnings

            BUILD FAILED - 0 non-fatal error(s), 1 warning(s)

            /root/opensim-0.6.8-release/OpenSim/Framework/Servers/HttpServer/OpenSim.Framework.Servers.HttpServer.dll.build(14,6):
            External Program Failed: /usr/lib/pkgconfig/../../lib/mono/2.0/gmcs.exe (return code was 1)

            Total time: 1.2 seconds.


BUILD FAILED

Nested build failed.  Refer to build log for exact reason.

Total time: 1.3 seconds.

OS is Fedora 7. Any ideas appreciated. :)