Silent panic in rust builder scope tests

[bilelmoussaoui]

test builder_rust_scope::tests::test_rust_builder_scope_closure ... okthread '<unnamed>' panicked at 'Closure returned a value of type guint64 but caller expected gchararray', C:\Users\runneradmin\.cargo\git\checkouts\gtk-rs-core-7be42ca38bd6361c\2ab14f6\glib\src\closure.rs:239:25

check the CI.

cc @jf2048

[jf2048]

This is an expected failure:

gtk4-rs/gtk4/src/builder_rust_scope.rs

Line 269 in ca06eb3

expected = "Closure returned a value of type guint64 but caller expected gchararray"

The problem here is that output is not being captured because this is a glib thread, it would probably be hidden if test_synced used a rust thread. Actually we can't capture output because rust's output capturing only works with threads spawned inside the test

[jf2048]

Relevant crate? https://crates.io/crates/gag

[jf2048]

This also could be an option if custom test frameworks are stabilized: rust-lang/rust#50297 (comment)

That would also save us any issues where things like g_warning and other C libraries produce output. But we probably should be using glib::log_set_handler in any case.