error from unitary plugin interface

[ajavadia]

the following fails

transpile(circuit, coupling_map=CouplingMap.from_line(8),
              layout_method='sabre', routing_method='sabre')

but it works on commits prior to #6124

The error is:

qiskit/transpiler/passes/synthesis/unitary_synthesis.py in run(self, dag)
    171         """
    172         if self.method not in self.plugins.ext_plugins:
--> 173             raise TranspilerError("Specified method: %s not found in plugin list" % self.method)
    174         default_method = self.plugins.ext_plugins["default"].obj
    175         plugin_method = self.plugins.ext_plugins[self.method].obj

TranspilerError: 'Specified method: default not found in plugin list'

[jakelishman]

You probably need to reinstall qiskit-terra - the plugin can't get registered as an entry point til you've rerun pip install -e . or whatever. If it's tox, you can rebuild the environment with tox -r.

This shouldn't happen on a clean install, only on a git checkout where you've pulled the new main without rerunning setup.py in some form or another.