Dealing with -output-directory

[wspr]

From a user a few years back:

I cope with huge documents with manifold auxilary file. Therefore, I create an output folder "LaTeX" for the aux-, index-, bib-, and glossary -files.
I do so by adding >>%& -aux-directory="LaTeX"<< before the documentclass declaration (not added right now!). However, pstool mixes up the directories and produces no output. I tried to change >>-output-directory="\pstool@path"<< to >>-output-directory=graphics<<, but in vain

Do you know how to circumvent this?

[mforbes]

I am having a potentially related issue:

# tst.tex
\documentclass{article}
\usepackage[process=all, mode=errorstop]{pstool}
\begin{document}
\begin{figure}[htpb]
  \begin{center}
    \psfragfig[width=8.6cm]{data/Dispersion}
  \end{center}
\end{figure}
\end{document}

1. Figure in ./data/Dispersion.eps.

2. psfrag commands in ./tst-pstool.tex.

3. Make output directory in ./_build:

   mkdir -p _build/data
   

4. Compile with

   pdflatex -shell-escape -output-directory="_build" "tst"

Gives error:

=== pstool: begin processing ===

=== pstool: auxiliary process: Dispersion  ===
This is pdfTeX, Version 3.14159265-2.6-1.40.18 (TeX Live 2017) (preloaded format=latex)
 \write18 enabled.
entering extended mode
! I can't find file `Dispersion-pstool.tex'.
<*> Dispersion-pstool.tex
                         
(Press Enter to retry, or Control-D to exit)
Please type another input file name: 

The Dispersion-pstool.tex is correctly created in ./_build/data/Dispersion-pstool.tex but for some reason pstool is looking for it in ./Dispersion-pstool.tex. If I manually move it there, things work.

mv ./_build/data/Dispersion-pstool.tex ./

If I run without specifying the output directory, then things work with ./data/Dispersion-pstool.tex being used.