lualatex bug confuses latexmk dependency tracking

Question

The described issue has been confirmed as a bug in luatex that can be expected to be solved in TeXLive 2018. Also latexmk itself has been extended to deal with this issue in version 4.55d.

For a large deck of lecture slides I am refactoring my custom Makefile into a more streamlined solution based on latexmk with the -use-make option.

While this works fine with pdflatex as engine, it causes lot's of make invocations with lualatex for targets that are actually part of the texmf tree. Minimal example:

% slides.tex
\RequirePackage{luatex85} 
\documentclass{beamer}

\begin{document}
  \begin{frame}{A Frame}
    Some content
  \end{frame}

\end{document}

If I compile this with

latexmk -lualatex -norc -use-make slides.tex

(-norc to make sure no hidden options are passed to latexmk)

Compilation works, but I get the following:

Latexmk: This is Latexmk, John Collins, 19 Jan. 2017, version: 4.52c.
Latexmk: 'lualatex': source file 'beamericonarticle.20.pdf' doesn't exist. I'll try making it...
------------
Running 'make "beamericonarticle.20.pdf"'
------------
make: *** No rule to make target `beamericonarticle.20.pdf'.  Stop.
Latexmk: 'lualatex': source file 'beamericonarticle.pdf' doesn't exist. I'll try making it...
------------
Running 'make "beamericonarticle.pdf"'
------------
make: *** No rule to make target `beamericonarticle.pdf'.  Stop.
<... and so on ..,>
Latexmk: All targets (slides.pdf) are up-to-date

I assume the culprit comes from the fact, that lualatex behaves slightly different to pdflatex with respect to the -recorder option, which is (AFAIK) employed by latexmk for input dependency tracking. In the lualatex version we find one extra line in the generated slides.fls file for every included image:

INPUT /opt/local/share/texmf-texlive/tex/latex/beamer/art/beamericonarticle.pdf
INPUT beamericonarticle.pdf      <-- not generated by pdflatex!
INPUT /opt/local/share/texmf-texlive/tex/latex/beamer/art/beamericonarticle.20.pdf
INPUT beamericonarticle.20.pdf   <-- not generated by pdflatex!

So apparently, latexmk does not know what to make out of these "extra" INPUTs and, thus, calls make to build them.

Employed Versions:

This is LuaTeX, Version 1.0.4 (TeX Live 2017/MacPorts 2017_2)

Latexmk, John Collins, 19 Jan. 2017. Version 4.52c

Questions:

• Is this a bug or a feature of lualatex?
• Or maybe the lua-specific part of the graphics driver is to blame here?
• Possible workarounds?

Answer 1

For those who are adventurous enough to fiddle around with the (amazingly well documented!) latexmk source code, I have a quick workaround:

The following lines should be inserted in parse_fls function definition (sub parse_fls):

4588         elsif (/^\s*INPUT\s+([^\/]*)$/) {
4589           # Ignore entries without any directory part
4590           # Those are additionally inserted in some versions of lualatex
4591           # see: https://tex.stackexchange.com/questions/420274
4592           next;
4593         }

Note that the line numbers will vary, depending on the precise version of latexmk. They should be inserted before the following existing lines:

4594         elsif (/^\s*INPUT\s+(.*)$/) {
4595             # Take precautions against aliasing of foo, ./foo and other possibilities for cwd.