A glitch (???) in tools::texi2pf.

On Sat, 28 Aug 2021 12:49:04 +0300
Eric Berger <ericjberger at gmail.com> wrote:

As Achim wrote in point (2), Makefile is your friend.

Well, all I can say is that Makefile is *not* my friend; I have never
made its acquaintance and wouldn't know where to begin looking.

Would it be possible for you to provide a template/prototype Makefile
and give me some idea what to *do* with it?

In a Makefile you can declare "rules" for producing certain "target" files 
from "prerequisite" files. The rules are only applied if any of the 
prerequisite files have changed since the target was last produced.

In your case the .bib is a prerequisite for the target .bbl which in turn 
is a prerequisite (along with the .tex) for the .pdf.

A nice introduction to GNU Make for data analysis workflows is this JSS 
paper by Peter Baker (http://petebaker.id.au/):

https://doi.org/10.18637/jss.v094.c01

Best wishes,
Z