BPE_APPEND_JAVA_TOOL_OPTIONS Concatenation Issue with paketo-buildpacks/builder-jammy-java-tiny

[ubermensch37]

BPE_APPEND_JAVA_TOOL_OPTIONS Concatenation Issue with paketo-buildpacks/builder-jammy-java-tiny

Expected Behavior

The BPE_APPEND_JAVA_TOOL_OPTIONS environment variable should append new Java tool options to the existing JAVA_TOOL_OPTIONS with a space as a separator. For example, if JAVA_TOOL_OPTIONS is -XX:ExitOnOutOfMemoryError and BPE_APPEND_JAVA_TOOL_OPTIONS is -XX:UseSVE=0, the resulting options should be -XX:ExitOnOutOfMemoryError -XX:UseSVE=0.

Current Behavior

BPE_APPEND_JAVA_TOOL_OPTIONS concatenates the new options directly to the existing JAVA_TOOL_OPTIONS without a space. Using the same example, the result is -XX:ExitOnOutOfMemoryError-XX:UseSVE=0. This leads to the JVM failing to recognize the options.

Possible Solution

Modify the buildpack logic to include a space when appending the value of BPE_APPEND_JAVA_TOOL_OPTIONS to JAVA_TOOL_OPTIONS. A simple fix would be to ensure a space is added between the existing options and the appended options.

Steps to Reproduce

1. Use the paketobuildpacks/builder-jammy-java-tiny buildpack (or a buildpack that uses this builder).
2. Set the BPE_APPEND_JAVA_TOOL_OPTIONS environment variable to -XX:UseSVE=0.
3. Build the image.
4. Attempt to run the application. It will likely fail with an "Unrecognized VM option" error.

Unrecognized VM option 'ExitOnOutOfMemoryError-XX:UseSVE=0'
Did you mean '(+/-)ExitOnOutOfMemoryError'?
Error: Could not create the Java Virtual Machine.
Error: A fatal exception has occurred. Program will exit.

Motivations

This issue is critical for running Java applications on M4 processors. The JDK on these processors often requires the -XX:UseSVE=0 option. Because of this bug, we cannot reliably deploy Java applications using the paketobuildpacks/builder-jammy-java-tiny buildpack on M4 architectures. This blocks us from utilizing these processors effectively. This issue is related to OpenJDK bug JDK-8345296.

[dmikusa]

Thanks for reaching out. If you have not, please try setting BPE_DELIM_JAVA_TOOL_OPTIONS=' '. The default delimiter is an empty string, which is why I believe that you're seeing this behavior.

https://github.com/paketo-buildpacks/environment-variables