There's two places that you need to add dependencies to a swift package, and the second snippet isn't typically included in project READMEs - depending on the package, it can be a little quirky or hard to work out what to use.
The first piece is what you copied - that adds a dependency stanza to the overall Package declaration. The second is what I suspect you were missing - adding a reference to the target that needs the dependency.
The second place, that wasn't obviously referenced in the README of the library project, is the bit you add to a specific target:
dependencies: [
.product(name: "SQLite", package: "SQLite.swift")
]
And to show you a fuller example, the Package.swift below is a quick-n-dirty example using the specific dependency you referenced:
// swift-tools-version: 5.8
import PackageDescription
let package = Package(
name: "temp",
products: [
.library(
name: "temp",
targets: ["temp"]),
],
dependencies: [
.package(url: "https://github.com/stephencelis/SQLite.swift.git", from: "0.14.1")
],
targets: [
.target(
name: "temp",
dependencies: [
.product(name: "SQLite", package: "SQLite.swift")
]
),
.testTarget(
name: "tempTests",
dependencies: ["temp"]),
]
)