Failed to locate library: liblwjgl.dylib

I am trying to create a Minecraft mod using this tutorial, altering the version to work with 1.15.1.

I moved a few files around to get it to work, but then this happened:

---- Minecraft Crash Report ----
// Everything's going to plan. No, really, that was supposed to happen.

Time: 12/04/20 1:44 PM
Description: Initializing game

java.lang.UnsatisfiedLinkError: Failed to locate library: liblwjgl.dylib
    at org.lwjgl.system.Library.loadSystem(Library.java:147)
    at org.lwjgl.system.Library.loadSystem(Library.java:67)
    at org.lwjgl.system.Library.<clinit>(Library.java:50)
    at org.lwjgl.system.MemoryUtil.<clinit>(MemoryUtil.java:97)
    at org.lwjgl.system.Pointer$Default.<clinit>(Pointer.java:61)
    at net.minecraft.client.MainWindow.func_211162_a(MainWindow.java:121)
    at com.mojang.blaze3d.platform.GLX._initGlfw(GLX.java:69)
    at com.mojang.blaze3d.systems.RenderSystem.initBackendSystem(RenderSystem.java:530)
    at net.minecraft.client.Minecraft.<init>(Minecraft.java:367)
    at net.minecraft.client.main.Main.main(Main.java:138)
    at inject.mcp.client.Start.main(Start.java:19)


A detailed walkthrough of the error, its code path and all known details is as follows:
---------------------------------------------------------------------------------------

-- Head --
Thread: Render thread
Stacktrace:
    at org.lwjgl.system.Library.loadSystem(Library.java:147)
    at org.lwjgl.system.Library.loadSystem(Library.java:67)
    at org.lwjgl.system.Library.<clinit>(Library.java:50)
    at org.lwjgl.system.MemoryUtil.<clinit>(MemoryUtil.java:97)
    at org.lwjgl.system.Pointer$Default.<clinit>(Pointer.java:61)
    at net.minecraft.client.MainWindow.func_211162_a(MainWindow.java:121)
    at com.mojang.blaze3d.platform.GLX._initGlfw(GLX.java:69)
    at com.mojang.blaze3d.systems.RenderSystem.initBackendSystem(RenderSystem.java:530)
    at net.minecraft.client.Minecraft.<init>(Minecraft.java:367)

-- Initialization --
Details:
Stacktrace:
    at net.minecraft.client.main.Main.main(Main.java:138)
    at inject.mcp.client.Start.main(Start.java:19)

-- System Details --
Details:
    Minecraft Version: 1.15.1
    Minecraft Version ID: 1.15.1
    Operating System: Mac OS X (x86_64) version 10.15.2
    Java Version: 1.8.0_241, Oracle Corporation
    Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Oracle Corporation
    Memory: 547425376 bytes (522 MB) / 862978048 bytes (823 MB) up to 1908932608 bytes (1820 MB)
    CPUs: 8
    JVM Flags: 0 total; 
    Launched Version: mcp
    Backend library: LWJGL version 3.2.1 build 12
    Backend API: ~~ERROR~~ NoClassDefFoundError: Could not initialize class org.lwjgl.system.Library
    GL Caps: 
    Using VBOs: Yes
    Is Modded: Very likely; Jar signature invalidated
    Type: Client (map_client.txt)
    CPU: <unknown>

It seems that it cannot locate the library "liblwjgl.dylib".

Upon checking for this library, I found a file that might match: liblwjgl.dylib.sha1 is located within the Project and external dependencies under lwjgl-3.2.1.jar

For some reason, however, that doesn't seem to work. I've not seen a file suffixed .sha1 before, what is it's a function? It contains one line, a hash (I am assuming sha1).

I am using macOS Catalina, Java 8 and Gradle 4.8.1 with Eclipse 4.15.0.