findByName() method returns null for gradle plugin task - gradle

Question

I am using maven-publish plugin. I have a publication called myMedia. When I try executing
tasks.findByName("publishMyMediaPublicationToSnapshotRepository"), it returns null. Why does it return null if there is a task by that name that maven-publish plugin created.
I'm not able to get around this issue. Any help is greatly appreciated.
EDIT 1 : START
I tried Francisco Mateo's suggestion to use the afterEvaluate method, but this too didn't seem to work for me.
However, while trying to figure out the actual cause I came across one interesting observation. I found that the when I call tasks.findByName("publishMyMediaPublicationToSnapshotRepository") from within a task, then it works perfectly fine and prints out the task, i.e. printTaskName runs as expected :
task printTaskName{
doLast{
println "task name found is :--- "+tasks.findByName("publishMyMediaPublicationToSnapshotRepository")
}
}
Now originally in my project's build.gradle I have a publishSnapshot task followed by ordering logic using mustRunAfter method:
task publishSnapshot (dependsOn: ['createMyMediaArchive','publishMyMediaPublicationToSnapshotRepository'])
tasks.findByName("publishMyMediaPublicationToSnapshotRepository").mustRunAfter tasks.findByName("createMyMediaArchive")
publishSnapshot.mustRunAfter tasks.findByName("publishMyMediaPublicationToSnapshotRepository")
executing the publishSnapshot task gives below error:
Cannot invoke method mustRunAfter() on null object
tasks.findByName method doesn't seem to work here as it returns null.
Am I missing out on some basics?
EDIT 1 : END
EDIT 2 : START
The below build.gradle is an edited version of what I actually have. I am not allowed to share the script. But the script is identical in structure to what I have. The rest of build script is as it is as far as the structure and syntax is concerned, just the names changed. Gradle version is 3.5.1
build.gradle
import java.time.LocalDate;
import java.time.format.DateTimeFormatter
import java.text.SimpleDateFormat
import Tasks.PublishArtifacts
import org.gradle.api.GradleException
buildscript {
repositories {
abcRelease()
}
dependencies {
classpath "org.codehaus.groovy.modules.http-builder:http-builder:0.7"
classpath "commons-collections:commons-collections:3.2.1"
classpath "org.jfrog.buildinfo:build-info-extractor-gradle:4.9.10"
}
}
repositories {
mavenCentral()
abcSnapshot()
xyzRelease()
}
apply plugin: 'maven-publish'
apply plugin: 'base'
apply plugin:'java'
apply from: "$rootDir/repositories.gradle"
def getMediaVersion(){
project.mediaVersion
}
configurations{
releaseMedia
}
publishing{
publications {
myMedia(MavenPublication) {
artifactId project.artifactId
artifact "$project.artifactId"+"-"+getMediaVersion()+".tgz"
version getMediaVersion()
}
}
repositories project.artifactoryRepositories
}
task publishSnapshot (dependsOn: ['createMyMediaArchive','publishMyMediaPublicationToSnapshotRepository'])
tasks.findByName("publishMyMediaPublicationToSnapshotRepository").mustRunAfter tasks.findByName("createMyMediaArchive")
publishSnapshot.mustRunAfter tasks.findByName("publishMyMediaPublicationToSnapshotRepository")
afterEvaluate { evaluated ->
evaluated.tasks.findByName("publishMyMediaPublicationToSnapshotRepository").configure {
println "My Media name --------- "+it.name
}
}
task printTaskName{
doLast{
println "task name found is :--- "+tasks.findByName("publishMyMediaPublicationToSnapshotRepository") // This returns task name as exected
}
}
task createMyMediaArchive{
doLast{
//code for creating media
}
}
EDIT 2 : END
EDIT 3: START
If I run the tasks individually, i.e. first running task createMyMediaArchive and then running task publishSnapshot ,where the taskpublishSnapshot depends on
task publishHelmMediaPublicationToSnapshotRepository, ie.
task publishSnapshot (dependsOn: ['publishHelmMediaPublicationToSnapshotRepository'])
then both the tasks run successfully. This proves that gradle does have the task publishHelmMediaPublicationToSnapshotRepository pre-configured.
Also gradlew tasks --all prints out this task.
This behavior is making things look more confusing to me.
EDIT 3 : END

Answer 1

A lot of the configuration performed by the maven-publish plugin is done lazily.
Wrapping in afterEvaluate should work.
afterEvaluate { evaluated ->
evaluated.tasks.findByName("publishMyMediaPublicationToSnapshotRepository").configure {
println it.name
}
}