build.gradle

buildscript {
    repositories {
        maven { url = 'https://files.minecraftforge.net/maven' }
        jcenter()
        mavenCentral()
    }
    dependencies {
        classpath 'net.minecraftforge.gradle:ForgeGradle:3.+'
    }
}

repositories {
    maven {
        // location of the maven that hosts JEI files
        name = "Progwml6 maven"
        url = "https://dvs1.progwml6.com/files/maven/"
    }
    maven {
        // location of a maven mirror for JEI files, as a fallback
        name = "ModMaven"
        url = "https://modmaven.k-4u.nl"
    }
}
        
apply plugin: 'net.minecraftforge.gradle'
// Only edit below this line, the above code adds and enables the necessary things for Forge to be setup.
apply plugin: 'eclipse'
apply plugin: 'maven-publish'

version = '1.0'
group = 'com.cydo.jei-recipe-extractor' // http://maven.apache.org/guides/mini/guide-naming-conventions.html
archivesBaseName = 'jei-recipe-extractor'

sourceCompatibility = targetCompatibility = compileJava.sourceCompatibility = compileJava.targetCompatibility = '1.8' // Need this here so eclipse task generates correctly.

minecraft {
    // The mappings can be changed at any time, and must be in the following format.
    // snapshot_YYYYMMDD   Snapshot are built nightly.
    // stable_#            Stables are built at the discretion of the MCP team.
    // Use non-default mappings at your own risk. they may not always work.
    // Simply re-run your setup task after changing the mappings to update your workspace.
    //mappings channel: 'snapshot', version: '20171003-1.12'
    mappings channel: 'snapshot', version: '20171003-1.12'
    // makeObfSourceJar = false // an Srg named sources jar is made by default. uncomment this to disable.
    
    // accessTransformer = file('src/main/resources/META-INF/accesstransformer.cfg')

    // Default run configurations.
    // These can be tweaked, removed, or duplicated as needed.
    runs {
        client {
            workingDirectory project.file('run')

            // Recommended logging data for a userdev environment
            property 'forge.logging.markers', 'SCAN,REGISTRIES,REGISTRYDUMP'

            // Recommended logging level for the console
            property 'forge.logging.console.level', 'debug'
        }

        server {

            // Recommended logging data for a userdev environment
            property 'forge.logging.markers', 'SCAN,REGISTRIES,REGISTRYDUMP'

            // Recommended logging level for the console
            property 'forge.logging.console.level', 'debug'
        }
    }
}

dependencies {
    // Specify the version of Minecraft to use, If this is any group other then 'net.minecraft' it is assumed
    // that the dep is a ForgeGradle 'patcher' dependency. And it's patches will be applied.
    // The userdev artifact is a special name and will get all sorts of transformations applied to it.
    minecraft 'net.minecraftforge:forge:1.12.2-14.23.5.2854'

    // You may put jars on which you depend on in ./libs or you may define them like so..
    // compile "some.group:artifact:version:classifier"
    // compile "some.group:artifact:version"

    // Real examples
    // compile 'com.mod-buildcraft:buildcraft:6.0.8:dev'  // adds buildcraft to the dev env
    // compile 'com.googlecode.efficient-java-matrix-library:ejml:0.24' // adds ejml to the dev env

    // The 'provided' configuration is for optional dependencies that exist at compile-time but might not at runtime.
    // provided 'com.mod-buildcraft:buildcraft:6.0.8:dev'

    // These dependencies get remapped to your current MCP mappings
    // deobf 'com.mod-buildcraft:buildcraft:6.0.8:dev'

    // For more info...
    // http://www.gradle.org/docs/current/userguide/artifact_dependencies_tutorial.html
    // http://www.gradle.org/docs/current/userguide/dependency_management.html

    // compile against the JEI API but do not include it at runtime
    deobf "mezz.jei:jei_${mc_version}:${jei_version}:api"
    // at runtime, use the full JEI jar
    runtime "mezz.jei:jei_${mc_version}:${jei_version}"

}

// Example for how to get properties into the manifest for reading by the runtime..
jar {
    manifest {
        attributes([
            "Specification-Title": "examplemod",
            "Specification-Vendor": "examplemodsareus",
            "Specification-Version": "1", // We are version 1 of ourselves
            "Implementation-Title": project.name,
            "Implementation-Version": "${version}",
            "Implementation-Vendor" :"examplemodsareus",
            "Implementation-Timestamp": new Date().format("yyyy-MM-dd'T'HH:mm:ssZ")
        ])
    }
}

// Example configuration to allow publishing using the maven-publish task
// This is the preferred method to reobfuscate your jar file
jar.finalizedBy('reobfJar') 
// However if you are in a multi-project build, dev time needs unobfed jar files, so you can delay the obfuscation until publishing by doing
//publish.dependsOn('reobfJar')

publishing {
    publications {
        mavenJava(MavenPublication) {
            artifact jar
        }
    }
    repositories {
        maven {
            url "file:///${project.projectDir}/mcmodsrepo"
        }
    }
}

error.txt

Could not resolve all files for configuration ':compileClasspath'.
> Could not find mezz.jei:jei_1.12.2:4.16.1.301_mapped_snapshot_20171003-1.12.
  Searched in the following locations:
    - https://dvs1.progwml6.com/files/maven/mezz/jei/jei_1.12.2/4.16.1.301_mapped_snapshot_20171003-1.12/jei_1.12.2-4.16.1.301_mapped_snapshot_20171003-1.12.pom
    - https://dvs1.progwml6.com/files/maven/mezz/jei/jei_1.12.2/4.16.1.301_mapped_snapshot_20171003-1.12/jei_1.12.2-4.16.1.301_mapped_snapshot_20171003-1.12-api.jar
    - https://modmaven.k-4u.nl/mezz/jei/jei_1.12.2/4.16.1.301_mapped_snapshot_20171003-1.12/jei_1.12.2-4.16.1.301_mapped_snapshot_20171003-1.12.pom
    - https://modmaven.k-4u.nl/mezz/jei/jei_1.12.2/4.16.1.301_mapped_snapshot_20171003-1.12/jei_1.12.2-4.16.1.301_mapped_snapshot_20171003-1.12-api.jar
    - https://files.minecraftforge.net/maven/mezz/jei/jei_1.12.2/4.16.1.301_mapped_snapshot_20171003-1.12/jei_1.12.2-4.16.1.301_mapped_snapshot_20171003-1.12.pom
    - https://files.minecraftforge.net/maven/mezz/jei/jei_1.12.2/4.16.1.301_mapped_snapshot_20171003-1.12/jei_1.12.2-4.16.1.301_mapped_snapshot_20171003-1.12-api.jar
    - file:/home/cydo/.gradle/caches/forge_gradle/bundeled_repo/mezz/jei/jei_1.12.2/4.16.1.301_mapped_snapshot_20171003-1.12/jei_1.12.2-4.16.1.301_mapped_snapshot_20171003-1.12.pom
    - file:/home/cydo/.gradle/caches/forge_gradle/bundeled_repo/mezz/jei/jei_1.12.2/4.16.1.301_mapped_snapshot_20171003-1.12/jei_1.12.2-4.16.1.301_mapped_snapshot_20171003-1.12-api.jar
    - https://libraries.minecraft.net/mezz/jei/jei_1.12.2/4.16.1.301_mapped_snapshot_20171003-1.12/jei_1.12.2-4.16.1.301_mapped_snapshot_20171003-1.12-api.jar
    - https://repo.maven.apache.org/maven2/mezz/jei/jei_1.12.2/4.16.1.301_mapped_snapshot_20171003-1.12/jei_1.12.2-4.16.1.301_mapped_snapshot_20171003-1.12.pom
    - https://repo.maven.apache.org/maven2/mezz/jei/jei_1.12.2/4.16.1.301_mapped_snapshot_20171003-1.12/jei_1.12.2-4.16.1.301_mapped_snapshot_20171003-1.12-api.jar
  Required by:
      project :

Possible solution:
 - Declare repository providing the artifact, see the documentation at https://docs.gradle.org/current/userguide/declaring_repositories.html

gradle.properties

# Sets default memory used for gradle commands. Can be overridden by user or command line properties.
# This is required to provide enough memory for the Minecraft decompilation process.
org.gradle.jvmargs=-Xmx3G
org.gradle.daemon=false
mc_version=1.12.2
jei_version=4.16.1.301
forge_version=14.23.5.2854