最近、JavaでLeetCodeを解いている。と言ってもEasyレベルのものばかりだけれど。
問題を解く途中でエラーに遭遇したので、顛末をメモしておく。
[Mavenプロジェクトの構成]
利用している環境は以下の通り。
$ mvn -version Apache Maven 3.6.2 (40f52333136460af0dc0d7232c0dc0bcf0d9e117; 2019-08-28T00:06:16+09:00) Maven home: /usr/local/Cellar/maven/3.6.2/libexec Java version: 13.0.1, vendor: Oracle Corporation, runtime: /Library/Java/JavaVirtualMachines/openjdk-13.0.1.jdk/Contents/Home Default locale: ja_JP, platform encoding: UTF-8 OS name: "mac os x", version: "10.15.6", arch: "x86_64", family: "mac"
Mavenプロジェクトの構成は至ってシンプル。App.javaやAppTest.javaの中身は今回あまり本筋とは関係ないので省略。
$ tree . ├── pom.xml └── src ├── main │ └── java │ └── com │ └── kdnakt │ └── simple │ └── App.java └── test └── java └── com └── kdnakt └── simple └── AppTest.java
pom.xmlの中身はおよそ以下の通り。
<!--?xml version="1.0" encoding="UTF-8"?--> <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemalocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"> <groupid>com.kdnakt.simple</groupid> <artifactid>simple-project</artifactid> <properties> <project.build.sourceencoding>UTF-8</project.build.sourceencoding> <maven.compiler.source>11</maven.compiler.source> <maven.compiler.target>11</maven.compiler.target> </properties> （略） <build> <pluginmanagement> <plugins> （略） <plugin> <artifactid>maven-surefire-plugin</artifactid> <version>2.22.1</version> </plugin> </plugins> </pluginmanagement> </build> （略） </project>
ここで指定されているmaven-surefire-pluginは、テストを実行しレポートを生成してくれるおなじみのMavenプラグインである。
[発生した例外]
テスト駆動開発よろしく失敗するテストを書き終えたので、mvn testコマンドでテストを実行しようとしたら、次のようにエラーログが出た。
$ mvn test [INFO] Scanning for projects... [INFO] [INFO] ------------------< com.kdnakt.simple:simple-project >------------------ [INFO] Building simple-project 1.0-SNAPSHOT [INFO] --------------------------------[ jar ]--------------------------------- [INFO] [INFO] --- maven-resources-plugin:3.0.2:resources (default-resources) @ simple-project --- [INFO] Using 'UTF-8' encoding to copy filtered resources. [INFO] skip non existing resourceDirectory /Users/akito/Develop/kdnakt/java-sandbox/simple'project/src/main/resources [INFO] [INFO] --- maven-compiler-plugin:3.8.0:compile (default-compile) @ simple-project --- [INFO] Changes detected - recompiling the module! [INFO] Compiling 1 source file to /Users/akito/Develop/kdnakt/java-sandbox/simple'project/target/classes [INFO] [INFO] --- maven-resources-plugin:3.0.2:testResources (default-testResources) @ simple-project --- [INFO] Using 'UTF-8' encoding to copy filtered resources. [INFO] skip non existing resourceDirectory /Users/akito/Develop/kdnakt/java-sandbox/simple'project/src/test/resources [INFO] [INFO] --- maven-compiler-plugin:3.8.0:testCompile (default-testCompile) @ simple-project --- [INFO] Changes detected - recompiling the module! [INFO] Compiling 1 source file to /Users/akito/Develop/kdnakt/java-sandbox/simple'project/target/test-classes [INFO] [INFO] --- maven-surefire-plugin:2.22.1:test (default-test) @ simple-project --- [INFO] [INFO] ------------------------------------------------------- [INFO] T E S T S [INFO] ------------------------------------------------------- [INFO] [INFO] Results: [INFO] [INFO] Tests run: 0, Failures: 0, Errors: 0, Skipped: 0 [INFO] [INFO] ------------------------------------------------------------------------ [INFO] BUILD FAILURE [INFO] ------------------------------------------------------------------------ [INFO] Total time: 2.300 s [INFO] Finished at: 2020-09-26T23:12:12+09:00 [INFO] ------------------------------------------------------------------------ [ERROR] Failed to execute goal org.apache.maven.plugins:maven-surefire-plugin:2.22.1:test (default-test) on project simple-project: There are test failures. [ERROR] [ERROR] Please refer to /Users/akito/Develop/kdnakt/java-sandbox/simple'project/target/surefire-reports for the individual test results. [ERROR] Please refer to dump files (if any exist) [date].dump, [date]-jvmRun[N].dump and [date].dumpstream. [ERROR] The forked VM terminated without properly saying goodbye. VM crash or System.exit called? [ERROR] Command was /bin/sh -c cd /Users/akito/Develop/kdnakt/java-sandbox/simple\'project && /Library/Java/JavaVirtualMachines/openjdk-13.0.1.jdk/Contents/Home/bin/java -jar '/Users/akito/Develop/kdnakt/java-sandbox/simple\'project/target/surefire/surefirebooter10150023550494437618.jar' '/Users/akito/Develop/kdnakt/java-sandbox/simple\'project/target/surefire' 2020-09-26T23-12-11_891-jvmRun1 surefire10720448871917931959tmp surefire_011591187786512401885tmp [ERROR] Error occurred in starting fork, check output in log [ERROR] Process Exit Code: 2 [ERROR] org.apache.maven.surefire.booter.SurefireBooterForkException: The forked VM terminated without properly saying goodbye. VM crash or System.exit called? [ERROR] Command was /bin/sh -c cd /Users/akito/Develop/kdnakt/java-sandbox/simple\'project && /Library/Java/JavaVirtualMachines/openjdk-13.0.1.jdk/Contents/Home/bin/java -jar '/Users/akito/Develop/kdnakt/java-sandbox/simple\'project/target/surefire/surefirebooter10150023550494437618.jar' '/Users/akito/Develop/kdnakt/java-sandbox/simple\'project/target/surefire' 2020-09-26T23-12-11_891-jvmRun1 surefire10720448871917931959tmp surefire_011591187786512401885tmp [ERROR] Error occurred in starting fork, check output in log [ERROR] Process Exit Code: 2 [ERROR] at org.apache.maven.plugin.surefire.booterclient.ForkStarter.fork(ForkStarter.java:669) [ERROR] at org.apache.maven.plugin.surefire.booterclient.ForkStarter.run(ForkStarter.java:282) [ERROR] at org.apache.maven.plugin.surefire.booterclient.ForkStarter.run(ForkStarter.java:245) [ERROR] at org.apache.maven.plugin.surefire.AbstractSurefireMojo.executeProvider(AbstractSurefireMojo.java:1183) [ERROR] at org.apache.maven.plugin.surefire.AbstractSurefireMojo.executeAfterPreconditionsChecked(AbstractSurefireMojo.java:1011) [ERROR] at org.apache.maven.plugin.surefire.AbstractSurefireMojo.execute(AbstractSurefireMojo.java:857) [ERROR] at org.apache.maven.plugin.DefaultBuildPluginManager.executeMojo(DefaultBuildPluginManager.java:137) [ERROR] at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:210) [ERROR] at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:156) [ERROR] at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:148) [ERROR] at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:117) [ERROR] at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:81) [ERROR] at org.apache.maven.lifecycle.internal.builder.singlethreaded.SingleThreadedBuilder.build(SingleThreadedBuilder.java:56) [ERROR] at org.apache.maven.lifecycle.internal.LifecycleStarter.execute(LifecycleStarter.java:128) [ERROR] at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:305) [ERROR] at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:192) [ERROR] at org.apache.maven.DefaultMaven.execute(DefaultMaven.java:105) [ERROR] at org.apache.maven.cli.MavenCli.execute(MavenCli.java:956) [ERROR] at org.apache.maven.cli.MavenCli.doMain(MavenCli.java:288) [ERROR] at org.apache.maven.cli.MavenCli.main(MavenCli.java:192) [ERROR] at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) [ERROR] at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) [ERROR] at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) [ERROR] at java.base/java.lang.reflect.Method.invoke(Method.java:567) [ERROR] at org.codehaus.plexus.classworlds.launcher.Launcher.launchEnhanced(Launcher.java:282) [ERROR] at org.codehaus.plexus.classworlds.launcher.Launcher.launch(Launcher.java:225) [ERROR] at org.codehaus.plexus.classworlds.launcher.Launcher.mainWithExitCode(Launcher.java:406) [ERROR] at org.codehaus.plexus.classworlds.launcher.Launcher.main(Launcher.java:347) [ERROR] [ERROR] -> [Help 1] [ERROR] [ERROR] To see the full stack trace of the errors, re-run Maven with the -e switch. [ERROR] Re-run Maven using the -X switch to enable full debug logging. [ERROR] [ERROR] For more information about the errors and possible solutions, please read the following articles: [ERROR] [Help 1] http://cwiki.apache.org/confluence/display/MAVEN/MojoExecutionException
[解決方法]
ググると以下のページがヒットした。
いくつか解決方法がありそうだったが、フォークしようとした際にエラーが発生しているので、フォークしないように以下の設定をpom.xmlに追加するという方法があった。
<plugin>
<artifactId>maven-surefire-plugin</artifactId>
<version>2.22.1</version>
+ <configuration>
+ <forkCount>0</forkCount>
+ </configuration>
</plugin>
試してみると、以下の通りうまく行った。
$ mvn test [INFO] Scanning for projects... [INFO] [INFO] ------------------< com.kdnakt.simple:simple-project >------------------ [INFO] Building simple-project 1.0-SNAPSHOT [INFO] --------------------------------[ jar ]--------------------------------- [INFO] [INFO] --- maven-resources-plugin:3.0.2:resources (default-resources) @ simple-project --- [INFO] Using 'UTF-8' encoding to copy filtered resources. [INFO] skip non existing resourceDirectory /Users/akito/Develop/kdnakt/java-sandbox/simple'project/src/main/resources [INFO] [INFO] --- maven-compiler-plugin:3.8.0:compile (default-compile) @ simple-project --- [INFO] Nothing to compile - all classes are up to date [INFO] [INFO] --- maven-resources-plugin:3.0.2:testResources (default-testResources) @ simple-project --- [INFO] Using 'UTF-8' encoding to copy filtered resources. [INFO] skip non existing resourceDirectory /Users/akito/Develop/kdnakt/java-sandbox/simple'project/src/test/resources [INFO] [INFO] --- maven-compiler-plugin:3.8.0:testCompile (default-testCompile) @ simple-project --- [INFO] Nothing to compile - all classes are up to date [INFO] [INFO] --- maven-surefire-plugin:2.22.1:test (default-test) @ simple-project --- [WARNING] useSystemClassloader setting has no effect when not forking [INFO] Running com.kdnakt.simple.AppTest [INFO] Tests run: 1, Failures: 0, Errors: 0, Skipped: 0, Time elapsed: 0.096 s - in com.kdnakt.simple.AppTest [INFO] [INFO] Results: [INFO] [INFO] Tests run: 1, Failures: 0, Errors: 0, Skipped: 0 [INFO] [INFO] ------------------------------------------------------------------------ [INFO] BUILD SUCCESS [INFO] ------------------------------------------------------------------------ [INFO] Total time: 2.301 s [INFO] Finished at: 2020-09-26T23:44:55+09:00 [INFO] ------------------------------------------------------------------------
また、ページの最後には、ブランチ名にダッシュ（-）が含まれている場合に同じエラーが発生しており、これを取り除くと問題なく動作したとの書き込みがあった。
今回はgitのmasterブランチで作業しており、ブランチ名には問題がないように思われた。
しかし、エラーメッセージが示しているdumpstreamファイルをみると、以下のように記載されており、`''あたりの記号が問題を引き起こしているようにも見えた。
$ cat target/surefire-reports/2020-09-26T23-43-55_712.dumpstream # Created at 2020-09-26T23:43:56.049 /bin/sh: -c: line 0: unexpected EOF while looking for matching `'' # Created at 2020-09-26T23:43:56.049 /bin/sh: -c: line 1: syntax error: unexpected end of file
よくよく思い出してみると、プロジェクトを作成したときのディレクトリ名がsimple'projectとシングルクオート(')を含んでいた。これを取り除いた別のディレクトリで、pom.xmlにフォーク数制限を設定する前のソースコードをコピーしてmvn testコマンドを実行すると、やはり問題なく動作した。
[まとめ]
mvn testコマンド実行時にSurefireBooterForkExceptionが発生したpom.xml上でフォーク数を0にする設定を追加すると問題が解消した- 別解として、プロジェクトのパスに含まれていたシングルクオートの記号を取り除いた場合も、問題が解消した
- 実装したサンプルコードは以下のリポジトリにまとめてある
無駄な記号はファイルパスに含めないにしましょう、というよくある教訓が得られた。もともとはLeetCodeの問題名をディレクトリ名に設定していて、Pascal's Triangleみたいな名前にしていたのがよくなかった、というオチ。
