Read build logs bottom-up, then jump to the first error

Build tools print in causal order and report in reverse. A Kotlin/Gradle-style run puts the compiler's own diagnostics (e: file.kt:42:9 Unresolved reference) near the top, then the task list, then the summary banner (BUILD FAILED in 2m 31s) at the bottom. The two pieces you need are therefore as far apart as they can be, and no fixed-size window from either end contains both.

tail -40 on that log shows > Task :app:compileKotlin FAILED and the banner. It does not show what failed to compile. The usual result is a second full build, purely to see a message that was already on disk.

The reading order that works: bottom for the verdict, then the first error marker for the cause. Never a fixed N.

The recorded case

In a multiplatform media app, this was raised repeatedly with the same automated assistant and kept recurring. Two distinct failures were recorded: