Yes it is possible and yes it has to do with the theming. You can check the default asciidoctor-pdf theming under https://github.com/asciidoctor/asciidoctor-pdf/blob/main/data/themes/default-theme.yml, you will see line 188 # code is used for source blocks (perhaps change to source or listing?)
, this is what you need to change.
The simplest way is to create your own theme custom-theme.yml
by extending the default theme and set the font family you want, in my example Courier, this works:
extends: default
font:
catalog:
merge: true
Courier:
normal: cour.ttf
bold: courbd.ttf
italic: couri.ttf
bold_italic: courbi.ttf
code:
font_family: Courier
I organize my files like this:
yourFile.adoc
resources/themes/custom-theme.yml
resources/fonts/cour.ttf
resources/fonts/courbd.ttf
resources/fonts/couri.ttf
resources/fonts/courbi.ttf
You then need to call asciidoctor-pdf
with your new theme and a link to the fonts path, something like this:
asciidoctor-pdf -a pdf-theme=resources/themes/custom-theme.yml -a pdf-fontsdir="resources/fonts;GEM_FONTS_DIR" yourFile.adoc