Unpacking of rpm failed

I am trying to run the alien command on an rpm package and get the below error.

Command:

sudo alien -k -i --scripts mypackage.rpm

Error:

Unpacking of 'mypackage.rpm' failed at /usr/share/perl5/Alien/Package/Rpm.pm line 168.

i tried running sudo apt install rpm --reinstall but still the error persists.NOTE - I have the above alien command in a .sh file and i get this error when running the shell script.

Also, when the run the below command(without shell script), it seems to work

rpm2cpio mypackage.rpm | cpio -i --make-directories18542 blocks

The line 168 at /usr/share/perl5/Alien/Package/Rpm.pm also does the same, i am not sure why the error then,