Errors occur when running `mvn package -DskipTests` and localizing bugs with flacoco jar

[DehengYang]

Dear Sirs,

I am very interested in this project and I am trying to package it on my pc for fault localization. I cloned this project and then ran mvn package -DskipTests, but it reports the following two types of compilation errors:

[ERROR] /home/apr/tools/flacoco/src/main/java/fr/spoonlabs/flacoco/core/test/strategies/testrunner/TestRunnerStrategy.java:[11,24] package org.apache.log4j does not exist [ERROR] /home/apr/tools/flacoco/src/main/java/fr/spoonlabs/flacoco/core/test/strategies/testrunner/TestRunnerStrategy.java:[29,13] cannot find symbol [ERROR] symbol: class Logger

[ERROR] /home/apr/tools/flacoco/src/main/java/fr/spoonlabs/flacoco/core/coverage/CoverageMatrix.java:[15,31] package org.jacoco.core.runtime does not exist

I think this could be resolved by adding the following dependencies into pom.xml:

    <dependency>
        <groupId>log4j</groupId>
        <artifactId>log4j</artifactId>
        <version>1.2.17</version>
    </dependency>

    <dependency>
        <groupId>org.jacoco</groupId>
        <artifactId>org.jacoco.core</artifactId>
        <version>0.8.7</version>
    </dependency>

With this workaround, I have used the flacoco-1.0.1-SNAPSHOT-jar-with-dependencies.jar to localize a bug in https://github.com/alibaba/fastjson/commit/96d0ee532a37351a126ebef2d5071964c33a1ec7 with the following command:

flacocoPath=/home/apr/tools/flacoco/target/flacoco-1.0.1-SNAPSHOT-jar-with-dependencies.jar
projPath=/home/apr/fastjson

java -jar $flacocoPath --projectpath $projPath

It failed with the following error:

[1522] WARN TestMethodFilter - NoClassDefFoundError: class com.alibaba.json.bvt.issue_1700.Issue1701
[1526] WARN TestMethodFilter - NoClassDefFoundError: class com.alibaba.json.bvt.cglib.TestCglib
[1531] WARN TestMethodFilter - NoClassDefFoundError: class com.alibaba.json.test.JsonIteratorImageTest
[1531] WARN TestMethodFilter - NoClassDefFoundError: class com.alibaba.json.test.Issue3805
[1533] WARN TestMethodFilter - NoClassDefFoundError: class com.alibaba.json.test.codec.Jackson2AfterBurnCodec
[1538] WARN TestMethodFilter - NoClassDefFoundError: class com.alibaba.json.test.benchmark.jdk10.generated.StringBenchmark_testParseJsonComp_jmhTest
[1539] WARN TestMethodFilter - NoClassDefFoundError: class com.alibaba.json.test.benchmark.jdk10.generated.StringBenchmark_jackson_testParseJson_jmhTest
[1539] WARN TestMethodFilter - NoClassDefFoundError: class com.alibaba.json.test.benchmark.jdk10.generated.StringBenchmark_testParseJson_jmhTest
[1539] WARN TestMethodFilter - NoClassDefFoundError: class com.alibaba.json.test.benchmark.jdk10.generated.StringBenchmark_jackson_testParseJsonComp_jmhTest
[1541] WARN TestMethodFilter - NoClassDefFoundError: class com.alibaba.json.test.JSONLibXmlTest
SLF4J: Failed to load class "org.slf4j.impl.StaticLoggerBinder".
SLF4J: Defaulting to no-operation (NOP) logger implementation
SLF4J: See http://www.slf4j.org/codes.html#StaticLoggerBinder for further details.
Exception in thread "main" java.lang.NoClassDefFoundError: org/jacoco/agent/rt/RT
    at eu.stamp_project.testrunner.EntryPoint.<clinit>(EntryPoint.java:868)
    at fr.spoonlabs.flacoco.core.coverage.framework.TestFrameworkStrategy.setupTestRunnerEntryPoint(TestFrameworkStrategy.java:32)
    at fr.spoonlabs.flacoco.core.coverage.framework.JUnit4Strategy.execute(JUnit4Strategy.java:25)
    at fr.spoonlabs.flacoco.core.coverage.CoverageRunner.getCoverageMatrix(CoverageRunner.java:49)
    at fr.spoonlabs.flacoco.localization.spectrum.SpectrumRunner.computeCoverageMatrix(SpectrumRunner.java:56)
    at fr.spoonlabs.flacoco.localization.spectrum.SpectrumRunner.run(SpectrumRunner.java:32)
    at fr.spoonlabs.flacoco.api.Flacoco.run(Flacoco.java:31)
    at fr.spoonlabs.flacoco.cli.FlacocoMain.call(FlacocoMain.java:157)
    at fr.spoonlabs.flacoco.cli.FlacocoMain.call(FlacocoMain.java:27)
    at picocli.CommandLine.executeUserObject(CommandLine.java:1953)
    at picocli.CommandLine.access$1300(CommandLine.java:145)
    at picocli.CommandLine$RunLast.executeUserObjectOfLastSubcommandWithSameParent(CommandLine.java:2352)
    at picocli.CommandLine$RunLast.handle(CommandLine.java:2346)
    at picocli.CommandLine$RunLast.handle(CommandLine.java:2311)
    at picocli.CommandLine$AbstractParseResultHandler.execute(CommandLine.java:2179)
    at picocli.CommandLine.execute(CommandLine.java:2078)
    at fr.spoonlabs.flacoco.cli.FlacocoMain.main(FlacocoMain.java:148)
Caused by: java.lang.ClassNotFoundException: org.jacoco.agent.rt.RT
    at java.net.URLClassLoader.findClass(URLClassLoader.java:382)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
    at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:349)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
    ... 17 more

Then I used the jar from the maven repo:

projPath=/home/apr/fastjson
flacocoPath=/home/apr/.m2/repository/com/github/spoonlabs/flacoco/1.0.0/flacoco-1.0.0.jar

java -cp $flacocoPath:/home/apr/tools/flacoco/target/dependency/* fr.spoonlabs.flacoco.cli.FlacocoMain --projectpath $projPath

It also failed with the same error.

Notes:

• the CLI usage of flacoco is obtained from https://github.com/SpoonLabs/flacoco/wiki/CLI and https://github.com/SpoonLabs/flacoco/wiki#usage-through-the-cli, where it claims to use fr.spoonlabs.flacoco.FlacocoMain but actually we should use fr.spoonlabs.flacoco.cli.FlacocoMain seemingly.
• the environment on my pc: JDK 8, maven 3.

It would be much appreciated if any advice could be provided. Thank you.

[andre15silva]

Dear Sirs,

Hi @DehengYang !

I am very interested in this project and I am trying to package it on my pc for fault localization.

Nice!

I cloned this project and then ran mvn package -DskipTests, but it reports the following two types of compilation errors:

[ERROR] /home/apr/tools/flacoco/src/main/java/fr/spoonlabs/flacoco/core/test/strategies/testrunner/TestRunnerStrategy.java:[11,24] package org.apache.log4j does not exist [ERROR] /home/apr/tools/flacoco/src/main/java/fr/spoonlabs/flacoco/core/test/strategies/testrunner/TestRunnerStrategy.java:[29,13] cannot find symbol [ERROR] symbol: class Logger

[ERROR] /home/apr/tools/flacoco/src/main/java/fr/spoonlabs/flacoco/core/coverage/CoverageMatrix.java:[15,31] package org.jacoco.core.runtime does not exist

That is weird. I'm not able to reproduce such error.

Could you post the entire log when running mvn package -DskipTests -X?

I think this could be resolved by adding the following dependencies into pom.xml:

  <dependency>
      <groupId>log4j</groupId>
      <artifactId>log4j</artifactId>
      <version>1.2.17</version>
  </dependency>

  <dependency>
      <groupId>org.jacoco</groupId>
      <artifactId>org.jacoco.core</artifactId>
      <version>0.8.7</version>
  </dependency>

You should not need to add the org.jacoco.core dependency as it already comes from test-runner.

The logging also works on my setup and in CI, so I don't really know what could be the issue.

With this workaround, I have used the flacoco-1.0.1-SNAPSHOT-jar-with-dependencies.jar to localize a bug in alibaba/fastjson@96d0ee5 with the following command:

flacocoPath=/home/apr/tools/flacoco/target/flacoco-1.0.1-SNAPSHOT-jar-with-dependencies.jar
projPath=/home/apr/fastjson

java -jar $flacocoPath --projectpath $projPath

It failed with the following error:

[1522] WARN TestMethodFilter - NoClassDefFoundError: class com.alibaba.json.bvt.issue_1700.Issue1701
[1526] WARN TestMethodFilter - NoClassDefFoundError: class com.alibaba.json.bvt.cglib.TestCglib
[1531] WARN TestMethodFilter - NoClassDefFoundError: class com.alibaba.json.test.JsonIteratorImageTest
[1531] WARN TestMethodFilter - NoClassDefFoundError: class com.alibaba.json.test.Issue3805
[1533] WARN TestMethodFilter - NoClassDefFoundError: class com.alibaba.json.test.codec.Jackson2AfterBurnCodec
[1538] WARN TestMethodFilter - NoClassDefFoundError: class com.alibaba.json.test.benchmark.jdk10.generated.StringBenchmark_testParseJsonComp_jmhTest
[1539] WARN TestMethodFilter - NoClassDefFoundError: class com.alibaba.json.test.benchmark.jdk10.generated.StringBenchmark_jackson_testParseJson_jmhTest
[1539] WARN TestMethodFilter - NoClassDefFoundError: class com.alibaba.json.test.benchmark.jdk10.generated.StringBenchmark_testParseJson_jmhTest
[1539] WARN TestMethodFilter - NoClassDefFoundError: class com.alibaba.json.test.benchmark.jdk10.generated.StringBenchmark_jackson_testParseJsonComp_jmhTest
[1541] WARN TestMethodFilter - NoClassDefFoundError: class com.alibaba.json.test.JSONLibXmlTest
SLF4J: Failed to load class "org.slf4j.impl.StaticLoggerBinder".
SLF4J: Defaulting to no-operation (NOP) logger implementation
SLF4J: See http://www.slf4j.org/codes.html#StaticLoggerBinder for further details.
Exception in thread "main" java.lang.NoClassDefFoundError: org/jacoco/agent/rt/RT
  at eu.stamp_project.testrunner.EntryPoint.<clinit>(EntryPoint.java:868)
  at fr.spoonlabs.flacoco.core.coverage.framework.TestFrameworkStrategy.setupTestRunnerEntryPoint(TestFrameworkStrategy.java:32)
  at fr.spoonlabs.flacoco.core.coverage.framework.JUnit4Strategy.execute(JUnit4Strategy.java:25)
  at fr.spoonlabs.flacoco.core.coverage.CoverageRunner.getCoverageMatrix(CoverageRunner.java:49)
  at fr.spoonlabs.flacoco.localization.spectrum.SpectrumRunner.computeCoverageMatrix(SpectrumRunner.java:56)
  at fr.spoonlabs.flacoco.localization.spectrum.SpectrumRunner.run(SpectrumRunner.java:32)
  at fr.spoonlabs.flacoco.api.Flacoco.run(Flacoco.java:31)
  at fr.spoonlabs.flacoco.cli.FlacocoMain.call(FlacocoMain.java:157)
  at fr.spoonlabs.flacoco.cli.FlacocoMain.call(FlacocoMain.java:27)
  at picocli.CommandLine.executeUserObject(CommandLine.java:1953)
  at picocli.CommandLine.access$1300(CommandLine.java:145)
  at picocli.CommandLine$RunLast.executeUserObjectOfLastSubcommandWithSameParent(CommandLine.java:2352)
  at picocli.CommandLine$RunLast.handle(CommandLine.java:2346)
  at picocli.CommandLine$RunLast.handle(CommandLine.java:2311)
  at picocli.CommandLine$AbstractParseResultHandler.execute(CommandLine.java:2179)
  at picocli.CommandLine.execute(CommandLine.java:2078)
  at fr.spoonlabs.flacoco.cli.FlacocoMain.main(FlacocoMain.java:148)
Caused by: java.lang.ClassNotFoundException: org.jacoco.agent.rt.RT
  at java.net.URLClassLoader.findClass(URLClassLoader.java:382)
  at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
  at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:349)
  at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
  ... 17 more

Then I used the jar from the maven repo:

projPath=/home/apr/fastjson
flacocoPath=/home/apr/.m2/repository/com/github/spoonlabs/flacoco/1.0.0/flacoco-1.0.0.jar

java -cp $flacocoPath:/home/apr/tools/flacoco/target/dependency/* fr.spoonlabs.flacoco.cli.FlacocoMain --projectpath $projPath

It also failed with the same error.

This could be related to the way you add the dependencies to the classpath. How did you generate them?

Notes:

* the CLI usage of flacoco is obtained from [SpoonLabs/flacoco/wiki/CLI](https://github.com/SpoonLabs/flacoco/wiki/CLI) and [SpoonLabs/flacoco/wiki#usage-through-the-cli](https://github.com/SpoonLabs/flacoco/wiki#usage-through-the-cli), where it claims to use `fr.spoonlabs.flacoco.FlacocoMain` but actually we should use `fr.spoonlabs.flacoco.cli.FlacocoMain` seemingly.

Thanks. I've updated the information there.

[DehengYang]

Hi @andre15silva ,

Thank you very much for your prompt reply!

That is weird. I'm not able to reproduce such error.

I could no longer reproduce this error, either. That's a weird build. Anyway, I can mvn clean package -DskipTest now without any error.

This could be related to the way you add the dependencies to the classpath. How did you generate them?

I have added the classpath now, but a new error arises:

[0] INFO Flacoco - Running Flacoco...
[1538] INFO EntryPoint - Path to runner Classes: /home/apr/tools/flacoco/target/flacoco-1.0.1-SNAPSHOT-jar-with-dependencies.jar
[1546] INFO EntryPoint - /home/apr/tools/flacoco/target/flacoco-1.0.1-SNAPSHOT-jar-with-dependencies.jar
[1546] INFO EntryPoint - /home/apr/tools/flacoco/target/flacoco-1.0.1-SNAPSHOT-jar-with-dependencies.jar
[1546] INFO EntryPoint - /home/apr/tools/flacoco/target/flacoco-1.0.1-SNAPSHOT-jar-with-dependencies.jar
[1546] INFO EntryPoint - /home/apr/tools/flacoco/target/flacoco-1.0.1-SNAPSHOT-jar-with-dependencies.jar
[1547] INFO EntryPoint - /home/apr/tools/flacoco/target/flacoco-1.0.1-SNAPSHOT-jar-with-dependencies.jar
[1547] INFO EntryPoint - /home/apr/tools/flacoco/target/flacoco-1.0.1-SNAPSHOT-jar-with-dependencies.jar
[1547] INFO EntryPoint - /home/apr/tools/flacoco/target/flacoco-1.0.1-SNAPSHOT-jar-with-dependencies.jar
[1547] INFO EntryPoint - /home/apr/tools/flacoco/target/flacoco-1.0.1-SNAPSHOT-jar-with-dependencies.jar
[1548] INFO EntryPoint - /home/apr/tools/flacoco/target/flacoco-1.0.1-SNAPSHOT-jar-with-dependencies.jar
[1548] INFO EntryPoint - /home/apr/tools/flacoco/target/flacoco-1.0.1-SNAPSHOT-jar-with-dependencies.jar
[1548] INFO EntryPoint - /home/apr/tools/flacoco/target/flacoco-1.0.1-SNAPSHOT-jar-with-dependencies.jar
java.lang.RuntimeException: Forked process did not finish correctly. Timeout set was 1000000 ms, process took 1000000 ms before ending.
    at eu.stamp_project.testrunner.EntryPoint.runGivenCommandLine(EntryPoint.java:764)
    at eu.stamp_project.testrunner.EntryPoint.runOnlineCoveredTestResultPerTestMethods(EntryPoint.java:656)
    at fr.spoonlabs.flacoco.core.coverage.framework.JUnit4Strategy.execute(JUnit4Strategy.java:27)
    at fr.spoonlabs.flacoco.core.coverage.CoverageRunner.getCoverageMatrix(CoverageRunner.java:47)
    at fr.spoonlabs.flacoco.localization.spectrum.SpectrumRunner.computeCoverageMatrix(SpectrumRunner.java:56)
    at fr.spoonlabs.flacoco.localization.spectrum.SpectrumRunner.run(SpectrumRunner.java:32)
    at fr.spoonlabs.flacoco.api.Flacoco.run(Flacoco.java:31)
    at fr.spoonlabs.flacoco.cli.FlacocoMain.call(FlacocoMain.java:157)
    at fr.spoonlabs.flacoco.cli.FlacocoMain.call(FlacocoMain.java:27)
    at picocli.CommandLine.executeUserObject(CommandLine.java:1953)
    at picocli.CommandLine.access$1300(CommandLine.java:145)
    at picocli.CommandLine$RunLast.executeUserObjectOfLastSubcommandWithSameParent(CommandLine.java:2352)
    at picocli.CommandLine$RunLast.handle(CommandLine.java:2346)
    at picocli.CommandLine$RunLast.handle(CommandLine.java:2311)
    at picocli.CommandLine$AbstractParseResultHandler.execute(CommandLine.java:2179)
    at picocli.CommandLine.execute(CommandLine.java:2078)
    at fr.spoonlabs.flacoco.cli.FlacocoMain.main(FlacocoMain.java:148)

My full command is as follows:

flacocoPath=/home/apr/tools/flacoco/target/flacoco-1.0.1-SNAPSHOT-jar-with-dependencies.jar
bug_dir="/home/apr/tests/fastjson"

src_java=${bug_dir}/"src/main/java/"
bin_java=${bug_dir}/"target/classes/"
bin_test=${bug_dir}/"target/test-classes/"
classpath=""

cd $bug_dir;
mvn dependency:copy-dependencies
cd -;

for file in ${bug_dir}/target/dependency/*
do
    if [[ $file == *".jar" ]]; then
        classpath="${classpath}:${file}"
    fi
done

echo -e "java -jar $flacocoPath --projectpath $bug_dir --classpath ${bin_java}:${bin_test}$classpath \n\n"

java -jar $flacocoPath --projectpath $bug_dir --classpath ${bin_java}:${bin_test}$classpath

#flacocoPath=/home/apr/.m2/repository/com/github/spoonlabs/flacoco/1.0.0/flacoco-1.0.0.jar
#java -cp $flacocoPath:/home/apr/tools/flacoco/target/dependency/* fr.spoonlabs.flacoco.cli.FlacocoMain --projectpath $projPath

Much appreciated if any advice could be offered. Thank you!

[andre15silva]

I could no longer reproduce this error, either. That's a weird build. Anyway, I can mvn clean package -DskipTest now without any error.

Great!

This could be related to the way you add the dependencies to the classpath. How did you generate them?

I have added the classpath now, but a new error arises:

[0] INFO Flacoco - Running Flacoco...
[1538] INFO EntryPoint - Path to runner Classes: /home/apr/tools/flacoco/target/flacoco-1.0.1-SNAPSHOT-jar-with-dependencies.jar
[1546] INFO EntryPoint - /home/apr/tools/flacoco/target/flacoco-1.0.1-SNAPSHOT-jar-with-dependencies.jar
[1546] INFO EntryPoint - /home/apr/tools/flacoco/target/flacoco-1.0.1-SNAPSHOT-jar-with-dependencies.jar
[1546] INFO EntryPoint - /home/apr/tools/flacoco/target/flacoco-1.0.1-SNAPSHOT-jar-with-dependencies.jar
[1546] INFO EntryPoint - /home/apr/tools/flacoco/target/flacoco-1.0.1-SNAPSHOT-jar-with-dependencies.jar
[1547] INFO EntryPoint - /home/apr/tools/flacoco/target/flacoco-1.0.1-SNAPSHOT-jar-with-dependencies.jar
[1547] INFO EntryPoint - /home/apr/tools/flacoco/target/flacoco-1.0.1-SNAPSHOT-jar-with-dependencies.jar
[1547] INFO EntryPoint - /home/apr/tools/flacoco/target/flacoco-1.0.1-SNAPSHOT-jar-with-dependencies.jar
[1547] INFO EntryPoint - /home/apr/tools/flacoco/target/flacoco-1.0.1-SNAPSHOT-jar-with-dependencies.jar
[1548] INFO EntryPoint - /home/apr/tools/flacoco/target/flacoco-1.0.1-SNAPSHOT-jar-with-dependencies.jar
[1548] INFO EntryPoint - /home/apr/tools/flacoco/target/flacoco-1.0.1-SNAPSHOT-jar-with-dependencies.jar
[1548] INFO EntryPoint - /home/apr/tools/flacoco/target/flacoco-1.0.1-SNAPSHOT-jar-with-dependencies.jar
java.lang.RuntimeException: Forked process did not finish correctly. Timeout set was 1000000 ms, process took 1000000 ms before ending.
  at eu.stamp_project.testrunner.EntryPoint.runGivenCommandLine(EntryPoint.java:764)
  at eu.stamp_project.testrunner.EntryPoint.runOnlineCoveredTestResultPerTestMethods(EntryPoint.java:656)
  at fr.spoonlabs.flacoco.core.coverage.framework.JUnit4Strategy.execute(JUnit4Strategy.java:27)
  at fr.spoonlabs.flacoco.core.coverage.CoverageRunner.getCoverageMatrix(CoverageRunner.java:47)
  at fr.spoonlabs.flacoco.localization.spectrum.SpectrumRunner.computeCoverageMatrix(SpectrumRunner.java:56)
  at fr.spoonlabs.flacoco.localization.spectrum.SpectrumRunner.run(SpectrumRunner.java:32)
  at fr.spoonlabs.flacoco.api.Flacoco.run(Flacoco.java:31)
  at fr.spoonlabs.flacoco.cli.FlacocoMain.call(FlacocoMain.java:157)
  at fr.spoonlabs.flacoco.cli.FlacocoMain.call(FlacocoMain.java:27)
  at picocli.CommandLine.executeUserObject(CommandLine.java:1953)
  at picocli.CommandLine.access$1300(CommandLine.java:145)
  at picocli.CommandLine$RunLast.executeUserObjectOfLastSubcommandWithSameParent(CommandLine.java:2352)
  at picocli.CommandLine$RunLast.handle(CommandLine.java:2346)
  at picocli.CommandLine$RunLast.handle(CommandLine.java:2311)
  at picocli.CommandLine$AbstractParseResultHandler.execute(CommandLine.java:2179)
  at picocli.CommandLine.execute(CommandLine.java:2078)
  at fr.spoonlabs.flacoco.cli.FlacocoMain.main(FlacocoMain.java:148)

My full command is as follows:

flacocoPath=/home/apr/tools/flacoco/target/flacoco-1.0.1-SNAPSHOT-jar-with-dependencies.jar
bug_dir="/home/apr/tests/fastjson"

src_java=${bug_dir}/"src/main/java/"
bin_java=${bug_dir}/"target/classes/"
bin_test=${bug_dir}/"target/test-classes/"
classpath=""

cd $bug_dir;
mvn dependency:copy-dependencies
cd -;

for file in ${bug_dir}/target/dependency/*
do
  if [[ $file == *".jar" ]]; then
      classpath="${classpath}:${file}"
  fi
done

echo -e "java -jar $flacocoPath --projectpath $bug_dir --classpath ${bin_java}:${bin_test}$classpath \n\n"

java -jar $flacocoPath --projectpath $bug_dir --classpath ${bin_java}:${bin_test}$classpath

#flacocoPath=/home/apr/.m2/repository/com/github/spoonlabs/flacoco/1.0.0/flacoco-1.0.0.jar
#java -cp $flacocoPath:/home/apr/tools/flacoco/target/dependency/* fr.spoonlabs.flacoco.cli.FlacocoMain --projectpath $projPath

Much appreciated if any advice could be offered. Thank you!

You are getting this message because the the test execution takes longer than the default timeout value (1000000 ms).

To increase the timeout, you can use the following option:

      --testRunnerTimeoutInMs=<testRunnerTimeoutInMs>
                            Timeout for each test execution with test-runner.
                              Must be greater than 0. Default value is 1000000

[DehengYang]

Thank you for the helpful guidance. But it's kinda weird that while mvn test only takes about two minutes, the localization process by flacoco takes over 1000s (about 16 minutes). What are the reasons for such time difference? Seemingly It is understandable, to a certain extent, that collecting the matrix might bring extra overhead.

I wonder if there is any approach or workaround to reduce the time cost of flacoco, especially for real-world large-scale projects? Please kindly advise. Thank you!

[monperrus]

Hi @DehengYang very good to meet you again and welcome to flacoco!

FYI, we're finishing a paper about flacoco, we'll let you know as soon as it's ready.

[DehengYang]

Hi Prof. @monperrus , thank you for the information and looking forward to that paper!

[andre15silva]

Hi @DehengYang ,

Sorry for the delayed response.

Thank you for the helpful guidance. But it's kinda weird that while mvn test only takes about two minutes, the localization process by flacoco takes over 1000s (about 16 minutes). What are the reasons for such time difference? Seemingly It is understandable, to a certain extent, that collecting the matrix might bring extra overhead.

Although there is some overhead, I'm surprised to see such a big difference. I will do some profiling efforts to see what is happening. Thanks for the information!

I wonder if there is any approach or workaround to reduce the time cost of flacoco, especially for real-world large-scale projects? Please kindly advise. Thank you!

There are a couple of ways of reducing the overhead, although it shouldn't be required for an usual case:

• Not executing all tests (you can use the --junit4tests and --junit5tests options to manually set which tests to run)
• Manually setting which classes to include in the coverage computation through the JaCoCo patterns (options --jacocoExcludes and --jacocoIncludes). This would override the automatic logic in place to select which classes are interesting, so you could further limit the scope of JaCoCo's, and therefore flacoco's, action.

[DehengYang]

Hi @andre15silva , thank you for the great help and useful guidance. I will try that soon.