build instructions?

[venkatperi]

Can you please add building instructions? There's a lot of inter project dependencies (e.g. swing depends on jvm8).

[jcornaz]

This is regular gradle build. You can use ./gradlew build to build everything. If you want to build only one module you can type: ./gradew :kotlinx-coroutines-swing:build (swing in this case). This would build any dependency first.

Just make sure you have a valid JAVA_HOME. (I have no problem with JDK 8)

[venkatperi]

The original issue was caused by IntelliJ's build (imported from Gradle).

However:
$ ./gradlew build throws the following error, even on a clean VM (docker run --rm -it openjdk:8 bash)

> Configure project :
Using Kotlin compiler version: 1.2.21


FAILURE: Build failed with an exception.

* What went wrong:
A problem occurred starting process 'command 'null/bin/java''
> Could not start 'null/bin/java'

* Try:
Run with --info or --debug option to get more log output.

* Exception is:
org.gradle.process.internal.ExecException: A problem occurred starting process 'command 'null/bin/java''
        at org.gradle.process.internal.DefaultExecHandle.execExceptionFor(DefaultExecHandle.java:222)
        at org.gradle.process.internal.DefaultExecHandle.setEndStateInfo(DefaultExecHandle.java:202)
        at org.gradle.process.internal.DefaultExecHandle.failed(DefaultExecHandle.java:342)
        at org.gradle.process.internal.ExecHandleRunner.run(ExecHandleRunner.java:86)
        at org.gradle.internal.operations.BuildOperationIdentifierPreservingRunnable.run(BuildOperationIdentifierPreservingRunnable.java:39)
        at org.gradle.internal.concurrent.ExecutorPolicy$CatchAndRecordFailures.onExecute(ExecutorPolicy.java:63)
        at org.gradle.internal.concurrent.ManagedExecutorImpl$1.run(ManagedExecutorImpl.java:46)
        at org.gradle.internal.concurrent.ThreadFactoryImpl$ManagedThreadRunnable.run(ThreadFactoryImpl.java:55)
Caused by: net.rubygrapefruit.platform.NativeException: Could not start 'null/bin/java'
        at net.rubygrapefruit.platform.internal.DefaultProcessLauncher.start(DefaultProcessLauncher.java:27)
        at net.rubygrapefruit.platform.internal.WrapperProcessLauncher.start(WrapperProcessLauncher.java:36)
        at org.gradle.process.internal.ExecHandleRunner.run(ExecHandleRunner.java:68)
        ... 4 more
Caused by: java.io.IOException: Cannot run program "null/bin/java" (in directory "/kotlinx.coroutines"): error=2, No such file or directory
        at net.rubygrapefruit.platform.internal.DefaultProcessLauncher.start(DefaultProcessLauncher.java:25)
        ... 6 more
Caused by: java.io.IOException: error=2, No such file or directory
        ... 7 more

[jcornaz]

"Could not start 'null/bin/java'" is a typical issue happening when JAVA_HOME is not set.

# Find the JDK
find /usr/lib/jvm/java-1.x.x-openjdk

# Set JAVA_HOME
export JAVA_HOME="path to the jdk"

# Verify (should print the path to the jdk)
echo $JAVA_HOME

# Try again
./gradlew build

[venkatperi]

Forgot to mention I verified JAVA_HOME was set:

root@55edb2697f0b:/# echo $JAVA_HOME
/docker-java-home

lrwxrwxrwx 1 root root 33 Mar 14 11:09 /docker-java-home -> /usr/lib/jvm/java-8-openjdk-amd64
lrwxrwxrwx 1 root root   20 Nov  1 14:17 java-1.8.0-openjdk-amd64 -> java-8-openjdk-amd64

[venkatperi]

This fails as well:

root@55edb2697f0b:/kotlinx.coroutines# echo $JAVA_HOME
/usr/lib/jvm/java-8-openjdk-amd64/

$ git clone https://github.com/Kotlin/kotlinx.coroutines
$ cd kotlinx.coroutines
$ ./gradlew build

[jcornaz]

What does $JAVA_HOME/bin/java -version return ?

[fvasco]

Use this Dockerfile to replace the issue

FROM openjdk:8
WORKDIR /home
RUN git clone https://github.com/Kotlin/kotlinx.coroutines .
RUN ./gradlew build -x test

Error:

:kotlinx-coroutines-core:jdk16Test FAILED

FAILURE: Build failed with an exception.

* What went wrong:
A problem occurred starting process 'command 'null/bin/java''
> Could not start 'null/bin/java'

* Try:
Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output.

* Get more help at https://help.gradle.org

BUILD FAILED in 5m 21s
25 actionable tasks: 25 executed
The command '/bin/sh -c ./gradlew build -x test' returned a non-zero code: 1

See

kotlinx.coroutines/core/kotlinx-coroutines-core/build.gradle

Line 28 in fcdce10

executable = "$System.env.JDK_16/bin/java"

[venkatperi]

root@9ba151b4bc7b:/# java -version
openjdk version "1.8.0_151"
OpenJDK Runtime Environment (build 1.8.0_151-8u151-b12-1~deb9u1-b12)
OpenJDK 64-Bit Server VM (build 25.151-b12, mixed mode)

Btw, JDK_16 is undefined per previous post. Could be the issue.

[venkatperi]

skipping task jdk16Test fixes the build

[jcornaz]

So yes, I agree the readme should tell to define JDK_16.

[venkatperi]

So 1.6 is needed in addition to the default/target jdk? Or why not skip the only 1.6 test if not defined and maybe print a msg saying it's skipped

[venkatperi]

Here's a pull request: #294

[fvasco]

Why running gradle with -x test executes jdk16Test?

kotlinx.coroutines/core/kotlinx-coroutines-core/build.gradle

Line 35 in fcdce10

build.dependsOn moreTest

[venkatperi]

While -x test will skip tests, the offending code is executed during grade's configure phase, hence the error.

[fvasco]

No, there is no reason to execute null/bin/java in configuration phase.
It is a dependency of build phase instead of test phase

(Please reopen this issue)

[venkatperi]

Gradle is failing during its config phase where it tries to create tasks (and their properties). I've created a new pull request to fail if JDK_16 is not set. #296

[fvasco]

Switch dependency fix the issue

-build.dependsOn moreTest
+test.dependsOn moreTest

gradle build -x test works