It came as a bit of a surprise that "prepend_path" INI settings propagate through the phase lineage (see below). I didn't realize that setting "prepend_path" in MPI get would set it from MPI Get through to Test run.
Code snippet from Run.pm: MTT::Values::ProcessEnvKeys($mpi_get, \@save_env); MTT::Values::ProcessEnvKeys($mpi_install, \@save_env); MTT::Values::ProcessEnvKeys($test_build, \@save_env); %$config = %$MTT::Defaults::Test_specify; $config->{setenv} = MTT::Values::Value($ini, $section, "setenv"); $config->{unsetenv} = MTT::Values::Value($ini, $section, "unsetenv"); $config->{prepend_path} = MTT::Values::Value($ini, $section, "prepend_path"); $config->{append_path} = MTT::Values::Value($ini, $section, "append_path"); MTT::Values::ProcessEnvKeys($config, \@save_env); I can see how this is both handy, but could also throw a monkey wrench into compatiblity testing (e.g., building tests in one environment, and running in another). -Ethan