checklink: work around sshfs brain-damage (issue3636)
With the follow_symlinks option, sshfs will successfully create links
while claiming it encountered an I/O error. In addition, depending on
the type of link, it may subsequently be impossible to delete the link
via sshfs. Our existing link to '.' will cause sshfs to think the link
is a directory, and thus cause unlink to give EISDIR. Links to
non-existent names or circular links will cause the created link to not even
be visible.
Thus, we need to create a new temporary file and link to that. We'll
still get a failure, but we'll be able to remove the link.
try:
import coverage
getattr(coverage, 'process_startup', lambda: None)()
except ImportError:
pass