GNU parallel seems to not work properly in Ubuntu:
bash$ seq 10 | parallel echo {}
bash$
Where are my numbers? For fixing this «problem» (misconfiguration will be a better description) you need to comment an option that is implicit in Ubuntu. Go to:
bash$ sudo vim /etc/parallel/config
And comment the only setting there:
#--tollef
And now GNU parallel works again as expected:
bash$ seq 10 | parallel echo {}
1
2
3
4
5
6
7
8
9
10
bash$
That's all 🙂