[dataimport] Fix use of _create_copyfrom_buffer() (related to #3845572)
This is used indirectly by SQLGenObjectStore when running on a
PostgreSQL database.
Regression introduced by commit 70056633085c.
try:
rtype, = __args__
except ValueError:
print 'USAGE: cubicweb-ctl shell <instance> detect_cycle.py -- <relation type>'
print
graph = {}
for fromeid, toeid in rql('Any X,Y WHERE X %s Y' % rtype):
graph.setdefault(fromeid, []).append(toeid)
from logilab.common.graph import get_cycles
for cycle in get_cycles(graph):
print 'cycle', '->'.join(str(n) for n in cycle)