BUG #14236: pg_upgrade failed

The following bug has been logged on the website:

Bug reference: 14236
Logged by: Tien Nguyen
Email address: nqtien310(at)gmail(dot)com
PostgreSQL version: 9.4.1
Operating system: Linux
Description:

To whom this might concern,

I upgraded Postgres from 8.4 -> 9.4 a couple of days ago using pg_upgrade
with -k ( hard link ) option
- /usr/pgsql-9.4/bin/pg_upgrade -k -d /var/lib/pgsql/data -D
/var/lib/pgsql/9.4/data -b /usr/bin/ -B /usr/pgsql-9.4/bin/

It worked fine until yesterday, the new database seem to be corrupted, it
returns a very weird error (I forgot to capture those errors). Therefor I
have to delete the new cluster
- rm -rf /var/lib/pgsql/9.4/data

And run the upgrade again, this time I get the following error
- pg_dump: query to get data of sequence
"asset_tracker_notifications_id_seq" returned 0 rows (expected 1)

There's a couple of things that are confusing me
- Why I can't run the upgrade now, is there any change this can be fixed
?
- What cause the new database to be corrupted, is it related to the -k (
hard link ) option ?
- What is the correct way to use the -k ( hard link ) options ?

Any help will be highly appreciated, we're gonna do the real upgrade on
Production next week , so this is very urgent, thanks in advanced