When exporting asynchronously with an essentially empty org-export-async-init-file, the
process fails with this backtrace:

Debugger entered--Lisp error: (invalid-read-syntax "#" 1 0)
  read(#<buffer  *load*>)
  load-with-code-conversion("/var/folders/1q/6syg63894h5bqlwp2jdh8r440000gn/T/o..." "/var/folders/1q/6syg63894h5bqlwp2jdh8r440000gn/T/o..." nil t)
  command-line-1(("-l" "/Users/iostapyshyn/.emacs.d/org-export.el" "-l" "/var/folders/1q/6syg63894h5bqlwp2jdh8r440000gn/T/o..."))
  command-line()
  normal-top-level()

I have tracked the issue down to this bit in org-export-process tmpfile:

(or (ignore-errors (funcall '#<subr F616e6f6e796d6f75732d6c616d626461_anonymous_lambda_77>
"paper.tex")) ...

Read doesn't like the '# syntax, seems like it should have been #' instead. I have quoted
the post-process lambda in org-latex-export-to-pdf (see attached diff) and it seems to
have fixed the issue for me. However it doesn't seem like a proper solution.

Emacs  : GNU Emacs 28.0.50 (build 1, x86_64-apple-darwin20.5.0, NS appkit-2022.50 Version 11.4 (Build 20F71))
 of 2021-06-20
Package: Org mode version 9.4.4 (release_9.4.4 @ /Users/iostapyshyn/emacs/nextstep/Emacs.app/Contents/Resources/lisp/org/)