There's a merged pull request on the void-packages repository

mozjs52: honors sysroot when used in cross-compile
https://github.com/void-linux/void-packages/pull/19058

Description:
From https://autotools.io/pkgconfig/cross-compiling.html

> To design a variable to contain a path that needs to be used at build
> time, such as the path where a generation script is, you can prefix it
> in the .pc file with the built-in variable ${pc_sysrootdir}.

Fixing broken cinnamon (mozjs52's only user) cross build.

---

I have a working cross-compile cinnamon at #18826 
But the big PR take too much time in Travis.

I have cinnamon 4.4 in testing, too.