The documentation doesn't go into much detail:

sourcePaths	"<path1>" ["<path2>" [...]]	Allows to customize the path where to look for source files (any folder "source" or "src" is automatically used as a source path if no sourcePaths setting is specified) - note that you usually also need to define "importPaths" as "sourcePaths" don't influence those

On Monday, 18 November 2019 at 21:44:06 UTC, WhatMeWorry wrote:
>
> The documentation doesn't go into much detail:
>
> sourcePaths	"<path1>" ["<path2>" [...]]	Allows to customize the path where to look for source files (any folder "source" or "src" is automatically used as a source path if no sourcePaths setting is specified) - note that you usually also need to define "importPaths" as "sourcePaths" don't influence those

sourcePaths are used when the package is compiled, importPaths are used for looking up imports so other packages which depends on the package knows where to look for them.