auto-upgrade: add an option to silence the safe-mismatch message
For well tested case, the message can get in the way, so we add a way to disable
it.
#!/usr/bin/env python3
import errno
import os
import sys
for f in sys.argv[1:]:
try:
print(f, '->', os.readlink(f))
except OSError as err:
if err.errno != errno.EINVAL:
raise
print(f, '->', f, 'not a symlink')
sys.exit(0)