failed connection in unit testing yields bogus error

[akaszynski]

When using export PYMAPDL_START_INSTANCE=False, you get an attribute error when you fail to connect:

        if not connected:
            raise IOError(
>               f"Unable to connect to MAPDL gRPC instance at {self._target_str}"
            )
E           AttributeError: 'MapdlGrpc' object has no attribute '_target_str'

src/ansys/mapdl/core/mapdl_grpc.py:383: AttributeError

[germa89]

I encounter this error while working on docker.

I believe it is because there is no MAPDL instance which PyMAPDL can connect to in the specified port and address, then when fails to connect (if not connected) it raise the IOError but that attribute _target_str does not exist. This attribute is actually _channel_str. This bug was introduced in #996 and fixed in #1025.

I'm closing the issue, but feel free to reopen it.