Running "texmfstart texexec main-file" from a unix shell.

When an error occurs, e.g. in the metapost processing, one gives an X to quit that part of tex-processing.

However the process goes on and on, because of the many successive invocations.

Control-C does not help.

Is there a way to stop the texexec processing from running? (other than opening another shell, finding the pid of the main process and killing that).