Facing problems with backtick (` `) commands with chef 12.16.42

Hello,

We recently upgraded chef-client from 12.6 to 12.16.42.
After the upgrade, it appears that ruby command execution (backtick syntax) is having problems.
During compilation phase, chef-client is not executing these commands. There are no error logs either.
Did anyone else experience such problem? Any pointers to go ahead are welcome.

Setup details: Ubuntu 14.04 with kernel 4.4.0-59.