Using enumitem & setlist, itemsep doesn't work with pandoc

Question

I'm using the enumitem package with a setlist header-include to customize definition lists, and it's working great, except that no matter what value I give to itemsep the vertical space between items remains unaffected. Similarly, parsep does not work. The other options in my setlist work as expected (leftmargin=15pt, labelwidth=\widthof{\bfseries99}, font=\normalfont). I'm writing in markdown and using YAML metadata and Pandoc to generate a PDF. Here is my metadata, followed by the Pandoc command I've been using:

[UPDATED EXAMPLE]

---
title: |
    | The Title of This Document Is Itself the Title
author: Me Myself
documentclass: apa7
classoption:
- doc
- donotrepeattitle
- 12pt
header-includes:
   - \affiliation{Lorem Ipsum Institute}
   - \shorttitle{shortish title}
   - \raggedright
   - \righthyphenmin=62
   - \lefthyphenmin=62
   - \usepackage{hanging}
   - \usepackage{setspace}
   - \setstretch{1.25}
   - \usepackage{enumitem}
   - \setlist[description]{itemsep=1in, leftmargin=15pt, labelwidth=\widthof{\bfseries99}, font=\normalfont}
   - \newfontfamily\GreekToMe[Scale=MatchLowercase]{EB Garamond}
   - \renewcommand{\abstractname}{   }
   - \abstract{\singlespacing\small{Lorem ipsum…}}
...

Here’s some text. I’m writing entirely in markdown. I am using a definition list as a way to align a bit of dialogue, like so:

A:
: Person A speaks to Person B, and drones on and on and on, just to illustrate why I’m using definition lists. When I used the package hanging, I lost my markdown formatting in the dialogue; e.g. the word “space” in the next line appeared in the PDF as \*space\* instead of *space*. Using the definition list, I get my hanging indent and keep my markdown formatting.

B:
: Person B says, Can I please have some *space*, man?

A:
: Person A says, No can do—even though `itemsep=1in`!

Pandoc command:

$ pandoc --pdf-engine=xelatex input.md -o output.pdf

And here is the resulting PDF:

I'm new to using LaTeX and Pandoc and YAML, and I won't be surprised if I'm missing something obvious. But it does seem weird that most options in the setlist are working and the vertical space ones are not.

Answer 1

For reasons that I don't understand, pandoc makes extensive use of the macro \tightlist which it seems to insert in every list it generates. The tightlist macro sets the list \itemsep and \parsep to 0pt which is why your changes using enumitem are being overridden. The simplest way to solve this is to simply add the line

   - \let\tightlist\relax

to your header-includes block. This will make \tightlist do nothing, and the settings you set with enumitem will be respected.

Unrelated, but the \affiliation macro is deprecated in the apa7 class. You're apparently supposed to use \authorsaffiliations according to the warning text.

To debug this sort of problem in the future, it can be helpful to have pandoc generate the .tex file instead of the .pdf so that you can inspect its code directly. Of course if you're new to LaTeX this might not be so helpful, but if you become more familiar with it, it will probably be a useful tool for debugging.