There is no Logcat in commonMain, and println is not a logger
Five targets, five sinks, and one of them discards your output silently.
Engineering
Compose, Kotlin, and multiplatform work — the mechanism under the symptom.
229 posts
Compose is growing a styles API, and it's for the gap theming never covered
MaterialTheme scopes values to a subtree, which is the wrong shape for reusable per-component configuration. Compose's styles direction addresses that gap; wrapper composables are the pattern to use today.
runTest skips your delays, which is why the flaky test passed
Virtual time makes a 30-second timeout instant — and makes a real-dispatcher leak invisible.
Source sets are a graph, and iosMain is not where you think it is
The default hierarchy creates intermediate source sets you never declared.
StateFlow drops what you needed and keeps what you didn't
Conflation turns two identical emissions into one, so a repeated event vanishes.
One failed child cancelled the whole screen, and the scope was the reason
Structured concurrency propagates failure upward by design. SupervisorJob is how you declare independence.
commonTest runs on every target, which is the point and the cost
One test, five executions. That is how you find platform bugs — and how one flaky test fails five jobs.
composeResources is not Android resources, and qualifiers resolve differently
Same folder names, different resolution. The accessor is typed, and a missing qualifier fails somewhere new.
Extending MaterialTheme beats replacing it, until it doesn't
Material models colour, type and shape. Everything else a design system needs — spacing, motion, semantic colour — has to be added. Extending with a parallel CompositionLocal is usually right; a full custom system rarely is.
kotlinx-datetime has no Calendar, and the timezone database ships per platform
Instant is unambiguous. LocalDateTime is not. The same arithmetic can disagree across targets.
expect/actual is not an interface, and the difference shows up at link time
An interface is resolved at runtime by an instance. expect/actual is resolved at compile time by the source set.
The iOS framework you export is an API, and nobody reviews it
Every public declaration in the shared module becomes Swift API. internal is the design tool.