Bug: Gradle build error: Supplied javaHome is not a valid folder. You supplied: /usr/local/sdkman/candidates/java/current

[hfhbd]

Environment:

• VS Code Version: 1.97.2
• Extension Version: 3.16.4
• JDK Type & Version: temurin, 21
• OS Type & Version: Linux

Step to Reproduce:

Use devcontainer (GitHub Codespaces)

{
    "image": "mcr.microsoft.com/devcontainers/java:21"
}

with a Gradle project

For example use this project: https://github.com/hfhbd/mavencentral and open it with GitHub Codespaces

Expected Behavior:
No issue when opening the Gradle project

Actual Behavior:

[info] [gradle-server] Gradle Server started, listening on 38591
[info] Gradle client connected to server
[info] [gradle-server] Downloading https://services.gradle.org/distributions/gradle-8.13-milestone-3-bin.zip
[info] [gradle-server] ...
[info] [gradle-server] ....
[info] [gradle-server] ..
[info] [gradle-server] ...
[info] Java Home: /usr/local/sdkman/candidates/java/current
[info] JVM Args: -Xmx2048m,-Dfile.encoding=UTF-8,-Duser.country=US,-Duser.language=en,-Duser.variant
[info] Gradle User Home: /home/vscode/.gradle
[info] Gradle Version: 8.13-milestone-3
[error] Error getting build for /workspaces/mavencentral: Supplied javaHome is not a valid folder. You supplied: /usr/local/sdkman/candidates/java/current

Related Issues:

[github-actions]

Hi Philip Wedemann (@hfhbd), I'm an AI Support assistant here to help with your issue. While the team reviews your request, I wanted to provide some possible tips and documentation that might help you in the meantime.

• Override the Gradle JVM Home in your workspace settings so the extension picks a folder Gradle can validate. In .devcontainer/devcontainer.json (or .vscode/settings.json) add:

"settings": {
  "java.import.gradle.java.home": "/usr/local/sdkman/candidates/java/current"
}

Adjust the path to the actual JDK folder if /current is a broken symlink (e.g. /usr/local/sdkman/candidates/java/21.0.x-temurin).

• As an alternative, set the Gradle property in gradle.properties:

org.gradle.java.home=/usr/local/sdkman/candidates/java/current

• See a similar report where overriding java.import.gradle.java.home fixed the “invalid javaHome” error:
• “The supplied javaHome seems to be invalid. I cannot find the java executable…” (#1325)
microsoft/vscode-gradle#1325

labels:

• bug

duplicateUrls: []

The team will respond to your issue shortly. I hope these suggestions are helpful in the meantime. If this comment helped you, please give it a 👍. If the suggestion was not helpful or incorrect, please give it a 👎. Your feedback helps us improve!

[Uplink036]

Maybe this will help future travels of this road, do note my problem was with java feature instead of just java base image.

In my search I found a similar response to the AI, albeit slightly different. the human response was this:

"containerEnv": {
	"JAVA_HOME": "/usr/lib/jvm/msopenjdk-current"
}

That specific path one could get by running which java which returned

$which java
/usr/lib/jvm/msopenjdk-current/bin/java

While this did get the variable to be the correct value, gradle did not respect or use it.

A solution that worked for me was to specify version,

	"image": "mcr.microsoft.com/devcontainers/java:3-25-trixie",
		"ghcr.io/devcontainers/features/java:1": {
			"version": "25", // Set this to "none" to get the same gradle error
			"installMaven": "false",
			"installGradle": "true"
		}

This got me the sdkman version which gradle wanted.

Simillar issue on the devcontainer java feature side.