actix: thread '' panicked at 'no Task is currently running'

Hi. We are encountering a panic during the execution of a migration script for an application running in production.

It happens when we run a script which makes a lot of calls through the actix-web which triggers about 1000+ calls to a sync actor.

It works fine for the first like 100 requests, then panic happens and the rest of the calls are served almost immediately without actually doing anything.

thread '<unnamed>' panicked at 'no Task is currently running', /home/tatrix/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-0.1.25/src/task_impl/mod.rs:44:9
note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.
stack backtrace:
   0: std::sys::unix::backtrace::tracing::imp::unwind_backtrace
             at libstd/sys/unix/backtrace/tracing/gcc_s.rs:49
   1: std::sys_common::backtrace::print
             at libstd/sys_common/backtrace.rs:71
             at libstd/sys_common/backtrace.rs:59
   2: std::panicking::default_hook::{{closure}}
             at libstd/panicking.rs:211
   3: std::panicking::default_hook
             at libstd/panicking.rs:227
   4: std::panicking::rust_panic_with_hook
             at libstd/panicking.rs:477
   5: std::panicking::begin_panic
             at libstd/panicking.rs:411
   6: futures::task_impl::with
             at /home/tatrix/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-0.1.25/src/task_impl/mod.rs:44
   7: futures::task_impl::current
             at /home/tatrix/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-0.1.25/src/task_impl/mod.rs:115
   8: <actix::address::channel::AddressSender<A>>::park
             at /home/tatrix/.cargo/registry/src/github.com-1ecc6299db9ec823/actix-0.7.5/src/address/channel.rs:372
   9: <actix::address::channel::AddressSender<A>>::try_send
             at /home/tatrix/.cargo/registry/src/github.com-1ecc6299db9ec823/actix-0.7.5/src/address/channel.rs:276
  10: <actix::address::Addr<A>>::try_send
             at /home/tatrix/.cargo/registry/src/github.com-1ecc6299db9ec823/actix-0.7.5/src/address/mod.rs:112

  /// application stack trace omitted

  15: <actix::sync::SyncContextEnvelope<A, M> as actix::address::envelope::EnvelopeProxy>::handle
             at /home/tatrix/.cargo/registry/src/github.com-1ecc6299db9ec823/actix-0.7.5/src/sync.rs:337
  16: <actix::address::envelope::Envelope<A> as actix::address::envelope::EnvelopeProxy>::handle
             at /home/tatrix/.cargo/registry/src/github.com-1ecc6299db9ec823/actix-0.7.5/src/address/envelope.rs:67
  17: <actix::sync::SyncContext<A>>::run
             at /home/tatrix/.cargo/registry/src/github.com-1ecc6299db9ec823/actix-0.7.5/src/sync.rs:237
  18: <actix::sync::SyncArbiter<A>>::start::{{closure}}
             at /home/tatrix/.cargo/registry/src/github.com-1ecc6299db9ec823/actix-0.7.5/src/sync.rs:115