Can't build from source

[josephcsible]

When I run ./gradlew build in a fresh Git checkout, it fails:

This mapping 'snapshot_20180504' was designed for MC 1.12! Use at your own peril.
#################################################
         ForgeGradle 2.3-SNAPSHOT-7764e3e
  https://github.com/MinecraftForge/ForgeGradle
#################################################
                 Powered by MCP
             http://modcoderpack.com
     by: Searge, ProfMobius, R4wk, ZeuX
     Fesh0r, IngisKahn, bspkrs, LexManos
#################################################
Found AccessTransformer: jei_at.cfg_jei_1.12-4.7.0.67_at.cfg
Found AccessTransformer: top_at.cfg_TheOneProbe-1.12-1.12-1.4.11-5_at.cfg
Found AccessTransformer: rftools_at.cfg_rftools-1.12-7.30_at.cfg
Found AccessTransformer: ctm_at.cfg_CTM-MC1.12-0.2.3.12_at.cfg
Found AccessTransformer: deepresonance_at.cfg
Found AccessTransformer: eleccore_at.cfg

FAILURE: Build failed with an exception.

* What went wrong:
A problem occurred configuring root project 'DeepResonance'.
> Could not resolve all dependencies for configuration ':deobfCompile'.
   > Could not resolve mezz.jei:jei_1.12.2:4.8.5.159.
     Required by:
         mcjty.deepresonance:DeepResonance:1.12-1.8.0
      > Could not resolve mezz.jei:jei_1.12.2:4.8.5.159.
         > Could not get resource 'https://modmaven.k-4u.nl/mezz/jei/jei_1.12.2/4.8.5.159/jei_1.12.2-4.8.5.159.pom'.
            > Could not HEAD 'https://modmaven.k-4u.nl/mezz/jei/jei_1.12.2/4.8.5.159/jei_1.12.2-4.8.5.159.pom'. Received status code 500 from server: Internal Server Error
   > Could not find mcjty.theoneprobe:TheOneProbe-1.12:1.12-1.4.20-12.
     Searched in the following locations:
         https://files.minecraftforge.net/maven/mcjty/theoneprobe/TheOneProbe-1.12/1.12-1.4.20-12/TheOneProbe-1.12-1.12-1.4.20-12.pom
         https://files.minecraftforge.net/maven/mcjty/theoneprobe/TheOneProbe-1.12/1.12-1.4.20-12/TheOneProbe-1.12-1.12-1.4.20-12.jar
         https://repo1.maven.org/maven2/mcjty/theoneprobe/TheOneProbe-1.12/1.12-1.4.20-12/TheOneProbe-1.12-1.12-1.4.20-12.pom
         https://repo1.maven.org/maven2/mcjty/theoneprobe/TheOneProbe-1.12/1.12-1.4.20-12/TheOneProbe-1.12-1.12-1.4.20-12.jar
         https://libraries.minecraft.net/mcjty/theoneprobe/TheOneProbe-1.12/1.12-1.4.20-12/TheOneProbe-1.12-1.12-1.4.20-12.pom
         https://libraries.minecraft.net/mcjty/theoneprobe/TheOneProbe-1.12/1.12-1.4.20-12/TheOneProbe-1.12-1.12-1.4.20-12.jar
         https://modmaven.k-4u.nl/mcjty/theoneprobe/TheOneProbe-1.12/1.12-1.4.20-12/TheOneProbe-1.12-1.12-1.4.20-12.pom
         https://modmaven.k-4u.nl/mcjty/theoneprobe/TheOneProbe-1.12/1.12-1.4.20-12/TheOneProbe-1.12-1.12-1.4.20-12.jar
         https://tehnut.info/maven/mcjty/theoneprobe/TheOneProbe-1.12/1.12-1.4.20-12/TheOneProbe-1.12-1.12-1.4.20-12.pom
         https://tehnut.info/maven/mcjty/theoneprobe/TheOneProbe-1.12/1.12-1.4.20-12/TheOneProbe-1.12-1.12-1.4.20-12.jar
         http://maven.covers1624.net/mcjty/theoneprobe/TheOneProbe-1.12/1.12-1.4.20-12/TheOneProbe-1.12-1.12-1.4.20-12.pom
         http://maven.covers1624.net/mcjty/theoneprobe/TheOneProbe-1.12/1.12-1.4.20-12/TheOneProbe-1.12-1.12-1.4.20-12.jar
         https://maven.mcmoddev.com/mcjty/theoneprobe/TheOneProbe-1.12/1.12-1.4.20-12/TheOneProbe-1.12-1.12-1.4.20-12.pom
         https://maven.mcmoddev.com/mcjty/theoneprobe/TheOneProbe-1.12/1.12-1.4.20-12/TheOneProbe-1.12-1.12-1.4.20-12.jar
         file:/home/joe/.gradle/caches/minecraft/deobfedDeps/mcjty/theoneprobe/TheOneProbe-1.12/1.12-1.4.20-12/TheOneProbe-1.12-1.12-1.4.20-12.pom
         file:/home/joe/.gradle/caches/minecraft/deobfedDeps/mcjty/theoneprobe/TheOneProbe-1.12/1.12-1.4.20-12/TheOneProbe-1.12-1.12-1.4.20-12.jar
     Required by:
         mcjty.deepresonance:DeepResonance:1.12-1.8.0

* Try:
Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output.

BUILD FAILED

Total time: 11.939 secs

[josephcsible]

I tracked this down to commit 2d1c04c. As such, assigning @Elec332.