BUG #13664: pg_restore fails with -j parameter when restoring 9.1 db onto 9.5 alpha db

The following bug has been logged on the website:

Bug reference:      13664
Logged by:          slava moudry
Email address:      slava@cloudflare.com
PostgreSQL version: 9.5alpha2
Operating system:   Linux ubuntu 3.8.0-33-generic #48~precise1-Ubuntu
Description:

I am trying to restore 9.1 dump into new 9.5 database.
pg_restore seems to hang indefinitely (not doing anything) when I set number
of jobs: "-j 4".
works fine if skipping "-j" setting. On same machine, 9.1 restores fine on
same host.
pg_restore is done intoSQL_ASCII database.