Package not installing on Mac but works on Linux

[jamesmbaazam]

@Karim-Mane First reported this on Slack, so I tried it on both MacOS and Linux. The former error'd but the latter worked.

Here's the error

> pak::pkg_install("epiverse-trace/epiversetheme")
                                                                           
→ Will install 1 package.
→ The package (0 B) is cached.
+ epiversetheme   0.1.0 👷🏽‍♀️🔧 (GitHub: 376dacc)
ℹ No downloads are needed, 1 pkg is cached
ℹ Building epiversetheme 0.1.0
✖ Failed to build epiversetheme 0.1.0 (2.2s)                             
Error:                                                                   
! error in pak subprocess
Caused by error in `stop_task_build(state, worker)`:
! Failed to build source package epiversetheme.
Full installation output:
* installing *source* package ‘epiversetheme’ ...
** this is package ‘epiversetheme’ version ‘0.1.0’
staged installation is only possible with locking
** using non-staged installation
sed: 1: "inst/pkgdown/_pkgdown.yml": command i expects \ followed by text
ERROR: configuration failed for package ‘epiversetheme’
* removing ‘/private/var/folders/vr/dn4r1_zj417drd1zr9301trw0000gp/T/RtmpvP9TBj/pkg-lib5c511e4c6dda/epiversetheme’
Type .Last.error to see the more details.

From my digging around, it can be traced to this line

epiversetheme/configure

Line 5 in 376dacc

sed -i "s/{{ version }}/$VERSION/g" inst/pkgdown/_pkgdown.yml

, which was introduced in the following commit c49ba5a.

It doesn't work for Mac because of the varied use of sed on both operating systems.