TeX Live and pdflatex from source

[Karl Berry]

Hi Nick - the main build documentation I and others have written:
https://tug.org/texlive/build.html (overview)
https://tug.org/texinfohtml/tlbuild.html (detailed manual)

It's not going to explain everything you want to do in a step-by-step
way. Because different people do so many different things with TeX,
that's not possible. I just try to explain how things work and what the
facilities are.  As Ken said, it's complicated. Sorry, but that's the
reality.

As stated somewhere in there, executables won't run out of the install
directory because all the support files are missing in that location.
You have to do something to transfer the executables after "make install"
to something resembling the TL "Master" tree (not in quantity, but in
structure).

One thing you have to decide is how often and from where you will take
updates, both of pdftex (the binary -- if you built from the current
repo, that is essentially a random snapshot of the development sources),
and of latex (the packages -- which are updated on CTAN and imported to
TL by me when they show up). Plus the fonts and other packages you need.

One option I can think of for you, that I think is the least amount of
"real" work, would be to install TL, and then move your own compiled
pdftex (and whatever else you need) into place over the installed
binaries. As long as you build from the last released sources, not the
current development source, that should be ok. Then you can decide when
and whether you ever want to update packages by doing the usual tlmgr
update.

BTW, you may find it useful to look at tinytex
(https://yihui.org/tinytex/), which is doing something similar, in terms
of a cut-down installation, though without the compiling of
sources. Which, as you've seen, is not the hard part.

Hope this helps,
karl