Are you running this directly in terminal? Or how?

However, only pdf file is required, everything else will be automatically set by default.

Abhijeet Singh , I was running in windows jupyter notebook. Anyway, now I am trying it in ubuntu 20.04 in virtual box. Installed gfortran and running it through the terminal.

I have solved the issue, and mentioning it here to help others facing the same issue:

while installing I get an error like this:

$ naccess installation program

$ ----------------------------

$ installing naccess in directory /home/sudipta/Naccess

$ created naccess - cshell script

$ compiling accall.f

accall.f:255:31:

255 | write(4,'(a,i)')

| 1

Error: Nonnegative width required in format string at (1)

This I solved by replacing it with "write(4,*)"

Dear Sudipta Dash

These discussions might be helpful, have a look:

1. https://www.biostars.org/p/276483/

2. https://stackoverflow.com/questions/tagged/bioinformatics

Kind Regards

Qamar Ul Islam