Detecting multiple Kotlin daemon sessions at build time refers to instances when more than one Kotlin compiler daemon is running simultaneously during the build process. This typically occurs due to improper cleanup or misconfiguration in the build environment. Each daemon consumes resources like memory and CPU, leading to potential slowdowns and resource contention.
Developers need to monitor this to ensure efficient build processes and avoid performance bottlenecks, ultimately contributing to a more streamlined and effective development workflow.
Potential causes of ‘detected multiple Kotlin daemon sessions at build/kotlin/sessions’ include:
Multiple instances of the Kotlin compiler running simultaneously: This can happen if the compiler is started multiple times, either manually or due to a script error.
Accidental multiple starts: Developers might inadvertently start the Kotlin compiler multiple times, especially when switching between different branches or configurations.
Compiler crashes and restarts: If the Kotlin compiler crashes, it might restart automatically, leading to multiple daemon sessions.
Interruptions during compilation: If the compilation process is interrupted (e.g., due to a system crash or manual termination), the compiler might restart, causing multiple sessions.
Gradle build cache issues: Problems with the Gradle build cache can also lead to multiple daemon sessions as the compiler tries to reconcile cached data.
Common scenarios during development where this issue might occur:
Switching branches: When switching between branches that have different dependencies or configurations, the compiler might start multiple times.
Continuous Integration (CI) systems: CI systems might inadvertently start the compiler multiple times if the build scripts are not properly configured.
Manual restarts: Developers manually restarting the compiler to clear issues or to switch configurations can lead to multiple sessions.
System crashes: Unexpected system crashes or power failures can cause the compiler to restart multiple times.
Script errors: Errors in build scripts or automation tools can cause the compiler to start multiple times unintentionally.
These scenarios can lead to performance issues, memory leaks, and slow build times, making it crucial to identify and address the root cause of multiple Kotlin daemon sessions.
Encountering the error ‘w detected multiple Kotlin daemon sessions at build/kotlin/sessions’ can significantly disrupt the build process and overall development workflow. This error typically indicates that multiple instances of the Kotlin daemon are running simultaneously, which can lead to conflicts and inconsistencies during the build process.
When multiple daemon sessions are detected, the build system may struggle to determine which daemon instance to use, resulting in failed builds or unexpected behavior. This can cause delays in development as developers need to troubleshoot and resolve the issue before proceeding with their work.
Additionally, repeated occurrences of this error can lead to frustration and decreased productivity.
To address this issue, developers may need to manually terminate the extra daemon sessions and clean the build cache. This can be a time-consuming process, especially if the error persists. Furthermore, frequent occurrences of this error may indicate underlying issues with the project’s configuration or the development environment, requiring further investigation and potential adjustments.
In summary, encountering multiple Kotlin daemon sessions during the build process can have a significant impact on the development workflow, leading to delays, frustration, and potential configuration issues that need to be resolved.
Stop all running Kotlin daemon processes: Run the following command in your terminal:
killall -9 kotlind
Clear the Kotlin daemon session directory: Delete all files and directories inside the build/kotlin/sessions directory:
rm -rf build/kotlin/sessions/*
Start a new Kotlin daemon process: Run your build process again to start a new Kotlin daemon session.
Check for multiple Kotlin daemon sessions: Use the lsof command to identify any running Kotlin daemon sessions:
lsof | grep kotlind
Stop any additional Kotlin daemon sessions: If you find any additional Kotlin daemon sessions, stop them using the kill command:
kill -9 <PID>
Adjust project settings: Ensure that the Kotlin plugin is correctly configured in your project. Add the Kotlin plugin to the common parent project or the root project, then remove the versions in the subprojects. If the parent project does not need the plugin, add apply false to the plugin line:
plugins {
id 'org.jetbrains.kotlin.jvm' version '1.5.10'
}
Clean the project: Run the following command to clean the project:
./gradlew clean
Rebuild the project: Finally, rebuild your project to ensure that the issue is resolved:
./gradlew build
By following these steps, you should be able to resolve the issue of multiple Kotlin daemon sessions.
To prevent multiple Kotlin daemon sessions at build time, follow these proactive measures and settings adjustments:
Single Daemon Session Configuration: Ensure only one Kotlin daemon session runs by adding kotlin.daemon=false to your gradle.properties file.
Clean Build Directories: Regularly clean your build directories using ./gradlew clean to remove any residual daemon sessions.
Incremental Compilation: Enable incremental compilation to reduce the need for multiple daemon sessions. Set kotlin.incremental=true in your gradle.properties.
Monitor Daemon Sessions: Use lsof to monitor and identify any running Kotlin daemon sessions. Terminate unnecessary sessions with kill.
Update Dependencies: Ensure all dependencies are up-to-date to avoid compatibility issues that might cause daemon conflicts.
Gradle Configuration Cache: Enable Gradle configuration cache to improve build performance and reduce daemon conflicts.
Add org.gradle.unsafe.configuration-cache=true to your gradle.properties.
Precise Backup: Enable precise backup for incremental compilation to minimize build time and avoid daemon conflicts. Add kotlin.compiler.preciseCompilationResultsBackup=true to your gradle.properties.
Avoid Manual Daemon Start: Refrain from manually starting the Kotlin daemon. Let the build system handle it automatically.
Implementing these measures will help maintain a single Kotlin daemon session and prevent build issues related to multiple sessions.
Detecting multiple Kotlin daemon sessions during the build process can significantly disrupt the development workflow, leading to performance issues, memory leaks, and slow build times. This error typically occurs due to improper cleanup or misconfiguration in the build environment, causing multiple instances of the Kotlin compiler daemon to run simultaneously.
Potential causes include:
Common scenarios where this issue might occur include:
To address this issue, developers can:
Proactive measures include:
Implementing these measures will help maintain a single Kotlin daemon session and prevent build issues related to multiple sessions, ensuring smooth development processes.