koverLog / koverHtmlReport and koverVerify report different line coverage

[realdadfish]

Describe the bug
Kover seems to have problems always agreeing on the actual covered lines in a module between koverLog / koverHtmlReport and koverVerify, where the former is correct and the latter is (sometimes) wrong.

For example, for my offline-ui module all is fine:

> Task :offline-ui:koverPrintCoverage
application line coverage: 93.578%
> Task :offline-ui:koverVerify FAILED

FAILURE: Build failed with an exception.
* What went wrong:
Execution failed for task ':offline-ui:koverVerify'.
> Rule violated: lines covered percentage is 93.578000, but expected maximum is 55

i.e. both report 93,578% coverage.

However, in the login-ui module it fails:

> Task :login-ui:koverPrintCoverage
application line coverage: 88.1818%
> Task :login-ui:koverVerify FAILED

FAILURE: Build failed with an exception.
* What went wrong:
Execution failed for task ':login-ui:koverVerify'.
> Rule violated: lines covered percentage is 66.853900, but expected minimum is 86

Cleaning the module was not enough to resolve the issue. Only by disabling Gradle's build cache via -Dorg.gradle.caching=false the wrongly reported value from the verification task vanished. This is only a problem of the koverVerify task, as koverHtmlReport also reported the correct value.

Environment

• Kover Gradle Plugin version: 0.9.4
• Gradle version: 9.1.0
• Kotlin project type: Kotlin/Multiplatform + Android
• Coverage Toolset (if customized in build script): Kover

[shanshin]

Hi, could you please describe your situation in more detail?
Do you have no aggregated reports and all reports are performed only on the project, is the problem happening in JVM or Android modules?
If I switch to using JaCoCo, does the problem persist?

[realdadfish]

This happens for single modules with Kotlin multiplatform enabled. These modules have no custom code for Android / JVM / any other platform, everything is kept in commonMain. I haven't switched back to Jacoco because of the problems I had with this in the past, I'm rather happily using Kover's internal coverage now. I'd also have to adapt my expected coverage values everywhere because Kover and Jacoco report different values; I'd only do that if absolutely necessary, i.e. if things like #775 would also be fixed by this.

[shanshin]

At the moment, we have decided to freeze the development of our own instrumentation agent (intellij) and use JaCoCo in the future.
If the issue is also reproduced in JaCoCo, then it might be worth trying to fix this problem there.

This issue is duplicates #738, and a small reproducer would be very helpful.

[realdadfish]

OK, I'll migrate to Jacoco then and check if it persists. Until then I'll close this ticket.

[realdadfish]

I had the chance to test with Jacoco, but I'm basically seeing the same results. I have a KMP module "logisticnetwork-data" for which koverLog reports a lower value than koverHtmlReport. Cleaning and disabling the Gradle cache did not help: