custom gradle plugin causes: Cannot configure the 'publishing' extension - gradle

Question

I have a custom gradle plugin in which custom task types and gradle configurations are added. When I apply this plugin before maven-publish it works perfectly fine. But when I add it after apply plugin: 'maven-publish', it fails with error message :
FAILURE: Build failed with an exception.
* Where:
Build file '/scratch/skgupta/git_storage/emdi/integtest/build.gradle' line: 38
* What went wrong:
A problem occurred evaluating root project 'integtest'.
> Cannot configure the 'publishing' extension after it has been accessed.
* 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: 7.6 secs
Here is the build.gradle file.
buildscript {
repositories {
maven {
url = "${artifactory_contextUrl}/repo"
}
}
dependencies {
classpath group: 'com.mycomp.proj', name: 'MyCustomPlugin', version: "${pluginVersion}", transitive: true
}
}
apply plugin: 'java'
apply plugin: 'maven-publish'
apply plugin: 'MyCustomPlugin' // WHen this line is moved above maven-publish, build works fine.
// add jar name and version
jar.archiveName='lrgemaas_small_deploy_3n.jar'
group = 'com.mycom.proj.test'
version = '1.0.3'
dependencies {
compile group: 'eaas.platform', name: 'registry-lookup-client', version: '0.1'
compile group: 'eaas.platform', name: 'registry-client', version: '0.1'
compile configurations.lrgConfig // This configuration is added by MyCustomPlugin
compile configurations.webdriver // This configuration is added by MyCustomPlugin
}
repositories {
maven {
url = "${artifactory_contextUrl}/repo"
}
}
publishing {
publications {
myPublicationName(MavenPublication) {
artifactId 'lrgemaas_small_deploy_3n'
artifact jar.archivePath
}
}
repositories {
maven {
url = "${artifactory_contextUrl}/${artifactory_repoName}"
credentials {
username = "${artifactory_user}"
password = "${artifactory_password}"
}
}
}
}
// workflow for build
defaultTasks 'clean','build','publish'
PS: I tried doing nothing in the custom plugin (i.e., simply return from apply method), but it still gives same error.

Answer 1

Simply replacing:
publishing {
publications {
...
}
}
with following:
publishing.publications {
...
}
worked for me!

Answer 2

Gradle is brittle regarding the order of the plugins. There is a discussion about this exact issue at
https://discuss.gradle.org/t/apply-maven-publish-plugin-from-init-script/2460
"Cool, so this is what happens.
DefaultPublishingExtension which is backing the 'publishing {}' block is a DeferredConfigurable. It's a mechanism that allows to register a configuration block to be executed when an extension is accessed. Unfortunately sometimes it causes unexpected behaviour if you access this kind of extension unawares. This is exactly the case when for example you try to get all the properties of a project (as the release plugin does here: https://github.com/townsfolk/gradle-release/blob/master/src/main/groovy/release/PluginHelper.groovy#L230"

Answer 3

FYI, I use a dynamic version and found that I had to define version prior to apply of my plugins. Probably because java or maven-publish sets the publication details upon application.

Answer 4

I upgraded gradle version from 2.1 to 2.12 and it solved this problem, fwiw.