Heroku - GIT Deployment Task :npmInstall FAILED - heroku

Question

I initialized a JHipster project and tried to deploy it to heroku. I did nothing more than that and get the error below. Im not sure where the problem is, either the Jhipster release im using or Heroku i think. Should i try switching to another version of JHipster, or could this possibly be an issue of my local setup (npm-, node-, java-, gralde-version)?
JHipster Version(s)
generator-jhipster#6.10.1
JHipster configuration
{
"generator-jhipster": {
"promptValues": {
"packageName": "io.profit.testify",
"nativeLanguage": "en"
},
"jhipsterVersion": "6.10.1",
"applicationType": "monolith",
"baseName": "priv",
"packageName": "io.profit.testify",
"packageFolder": "io/profit/testify",
"serverPort": "8080",
"authenticationType": "jwt",
"cacheProvider": "ehcache",
"enableHibernateCache": false,
"websocket": false,
"databaseType": "sql",
"devDatabaseType": "h2Disk",
"prodDatabaseType": "postgresql",
"searchEngine": false,
"messageBroker": false,
"serviceDiscoveryType": false,
"buildTool": "gradle",
"enableSwaggerCodegen": false,
"jwtSecretKey": "YourJWTSecretKeyWasReplacedByThisMeaninglessTextByTheJHipsterInfoCommandForObviousSecurityReasons",
"embeddableLaunchScript": false,
"useSass": true,
"clientPackageManager": "npm",
"clientFramework": "angularX",
"clientTheme": "none",
"clientThemeVariant": "",
"creationTimestamp": 1595760910320,
"testFrameworks": [],
"jhiPrefix": "jhi",
"entitySuffix": "",
"dtoSuffix": "DTO",
"otherModules": [],
"enableTranslation": true,
"nativeLanguage": "en",
"languages": ["en", "de"],
"blueprints": [],
"herokuAppName": "afternoon-falls-71420",
"herokuDeployType": "git",
"herokuJavaVersion": "11"
}
}
Environment and Tools
java version "11.0.6" 2020-01-14 LTS
Java(TM) SE Runtime Environment 18.9 (build 11.0.6+8-LTS)
Java HotSpot(TM) 64-Bit Server VM 18.9 (build 11.0.6+8-LTS, mixed mode)
git version 2.20.1.windows.1
node: v12.2.0
npm: 6.9.0
yeoman: 3.1.1
Error From Heroku Console:
Downloading https://services.gradle.org/distributions/gradle-6.5-bin.zip
remote: .................................................................................................
remote: To honour the JVM settings for this build a new JVM will be forked. Please consider using the daemon: https://docs.gradle.org/6.5/userguide/gradle_daemon.html.
remote: Daemon will be stopped at the end of the build stopping after processing
remote: > Task :bootBuildInfo
remote: > Task :nodeSetup SKIPPED
remote: > Task :npmSetup SKIPPED
remote: > Task :npmInstall FAILED
remote:
remote: FAILURE: Build failed with an exception.
remote:
remote: * What went wrong:
remote: Execution failed for task ':npmInstall'.
remote: > A problem occurred starting process 'command 'npm''

Answer 1

If you want to set the correct gradle task you can set it manually via heroku cli:
heroku config:set GRADLE_TASK="stage -Pprod -PnodeInstall"
In case the buildpack is not correctly set configure it via
heroku buildpacks:add heroku/gradle
After that try pushing again via
git push heroku master
And the build should work again.