"writing to child signal FD: Bad file descriptor" message when opening a LaTeX document's PDF file using the Run Viewer button

[Evan Aad]

I created the following LaTeX document in Emacs:

\documentclass{article}
\begin{document}
Hello, world!
\end{document}

I saved this document in a file named "mydoc.tex" inside my home directory "~/".

I then processed the document through a LaTeX engine by executing the
following commands in a Terminal window:

> pdflatex mydoc

The command ran successfully, and produced a pdf file named "~/mydoc.pdf".

I then hit the "Run Viewer" button in the Emacs GUI's toolbar (i.e.
the button showing a pair of glasses with the label "PDF" under them).
This button is supposed to open the PDF file associated with the TeX
document in the current buffer. And this is indeed what happened.
However, at the same time the following message appeared in the
Terminal window:

/Applications/Emacs.app/Contents/MacOS/Emacs-x86_64-10_14: writing to
child signal FD: Bad file descriptor

This message is appended to the Terminal window every time I hit the
"Run Viewer" button.

How can I fix whatever problem it is that causes this message to appear?

***

System info:

Computer: iMac, late 2013
OS: macOS Catalina, v. 10.15.7
Emacs: GNU Emacs, v. 28.2 (9.0)
pdflatex version: 3.141592653-2.6-1.40.24 (TeX Live 2022)