Using `sem` to make a script run in parallel

I have the following shell script (one liner), which I wanted to use to identify directories that have the exact same contents. I'm using it, to identify and remove duplicate (child) directories. When I try to run the same script with sem, I encounter No such file or directory errors. **Example - no parallel threads** find -type d -links 2 | while read i; do \ find "$i" -type f -print0 | xargs -r0 md5sum | awk '{ print $1 }' \ | sort | md5sum | xargs -I {} echo {} $i ; \ done Gives me: e94d32e2a683d46d49c7580d649f7888 - ./Daft Punk/Alive 2007 2 e94d32e2a683d46d49c7580d649f7888 - ./Daft Punk/Alive 2007 --- **Example - using sem** find -type d -links 2 | while read i; do sem -j+0 \ find "$i" -type f -print0 | xargs -r0 md5sum | awk '{ print $1 }' \ | sort | md5sum | xargs -I {} echo {} $i ; \ done; sem --wait Gives me: find: `./Daft': No such file or directory find: `Punk/Alive': No such file or directory find: `2007': No such file or directory find: `2': No such file or directory d41d8cd98f00b204e9800998ecf8427e - ./Daft Punk/Alive 2007 2 find: `./Daft': No such file or directory find: `Punk/Alive': No such file or directory find: `2007': No such file or directory d41d8cd98f00b204e9800998ecf8427e - ./Daft Punk/Alive 2007 ### Questions: 1. Why the difference in behaviour? 1. How do I remove/fix the No such file or directory from the sem script? 1. Are there any other improvements I could make in the script? (there is lots of awk and xargs)