What's this gap in the build timeline?

Help/Discuss
1

I’m using Gradle with the Develocity plugin to understand build performance on CI. There’s a chunk of time at the start of the build where nothing appears to be happening, and nothing in the logs that explains why.

Here’s the relevant part of the log, from the start of the build.

14:19:38 Welcome to Gradle 8.14.4!
14:19:38 Here are the highlights of this release:
14:19:38  - Java 24 support
14:19:38  - GraalVM Native Image toolchain selection
14:19:38  - Enhancements to test reporting
14:19:38  - Build Authoring improvements
14:19:38 For more details see https://docs.gradle.org/8.14.4/release-notes.html
14:19:38 Starting a Gradle Daemon (subsequent builds will be faster)
14:19:38 Daemon JVM discovery is an incubating feature.
14:20:06 Type-safe project accessors is an incubating feature.
14:20:28 > Task :build-logic:convention:checkKotlinGradlePluginConfigurationErrors SKIPPED
14:20:33 > Task :build-logic:convention:pluginDescriptors
...

(setting the log devel to debug (e.g., passing -d on the command-line) is a non-starter, see Logging )

What’s going on between:

14:19:38 Daemon JVM discovery is an incubating feature.
14:20:06 Type-safe project accessors is an incubating feature.

? That’s 28 seconds of unaccounted for time in the build, and a significant portion of the build time.

In the Develocity timeline view this appears as blank space, nothing going on. But something is happening, based on the spikes in CPU and Network activity during the blank region:

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2

Maybe have a go with the gradle-profiler to find out what is happening and maybe report about it.

3

I don’t understand why you think gradle-profiler is the right tool here.

I’m already using build scans (one of gradle-profiler’s options, which highlighted the problem. The other options/backends for gradle-profiler seem to be about e.g., measuring CPU or heap use.

I can already see that information in the build scan. What’s missing is the higher level “These are the Gradle-centric operations in progress that are on the critical path for the build to actually start”.

4

Well, you said you cannot show debug logs.
So how could anyone guess what is happening in a gap?
With a profiler you should be able to determine what is happening in the timeframe hopefully.