gistfile1.txt

#[derive(Clone)]
pub struct Scope {
    pub(crate) fingerprint: Option<Arc<Vec<Cow<'static, str>>>>,
    pub(crate) transaction: Option<Arc<String>>,
    pub(crate) breadcrumbs: im::Vector<Breadcrumb>,
    pub(crate) user: Option<Arc<User>>,
    pub(crate) extra: im::HashMap<String, Value>,
    pub(crate) tags: im::HashMap<String, String>,
    pub(crate) contexts: im::HashMap<String, Option<Context>>,
    pub(crate) scope_processors: im::Vector<Box<FnMut(&mut Event) + Sync + Send>>,
}

    /// Registers a processing function with the scope.
    pub fn add_scope_processor<F: FnMut(&mut Event) + Sync + Send>(&mut self, f: F) {
        self.scope_processors = self.scope_processors.push_back(Box::new(f));
    }


error[E0277]: the trait bound `std::boxed::Box<F>: im::shared::Shared<std::boxed::Box<for<'r, 's> std::ops::FnMut(&'r mut sentry_types::protocol::v7::Event<'s>) + std::marker::Sync + std::marker::Send>>` is not satisfied
   --> src/scope/real.rs:234:55
    |
234 |         self.scope_processors = self.scope_processors.push_back(Box::new(f));
    |                                                       ^^^^^^^^^ the trait `im::shared::Shared<std::boxed::Box<for<'r, 's> std::ops::FnMut(&'r mut sentry_types::protocol::v7::Event<'s>) + std::marker::Sync + std::marker::Send>>` is not implemented for `std::boxed::Box<F>`
    |
    = help: consider adding a `where std::boxed::Box<F>: im::shared::Shared<std::boxed::Box<for<'r, 's> std::ops::FnMut(&'r mut sentry_types::protocol::v7::Event<'s>) + std::marker::Sync + std::marker::Send>>` bound 

I think it's

pub fn add_scope_processor<F: FnMut(&mut Event) + Sync + Send>(&mut self, f: F)
  where std::boxed::Box<F>: im::shared::Shared<std::boxed::Box<for<'r, 's> std::ops::FnMut(&'r mut sentry_types::protocol::v7::Event<'s>) + std::marker::Sync + std::marker::Send>>
{
    self.scope_processors = self.scope_processors.push_back(Box::new(f));
}

you can probably remove some of the qualified trait/struct names there to make it less verbose