Address already in use

[peterjaap]

I'm using the Ubuntu build and getting this;

export RUST_BACKTRACE=1 && ./config-gen http://example.com/ --config config-gen.yml
thread 'main' panicked at 'Couldn't start the application: Os { code: 98, kind: AddrInUse, message: "Address already in use" }', libcore/result.rs:1009:5
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:476
   5: std::panicking::continue_panic_fmt
             at libstd/panicking.rs:390
   6: rust_begin_unwind
             at libstd/panicking.rs:325
   7: core::panicking::panic_fmt
             at libcore/panicking.rs:77
   8: core::result::unwrap_failed
   9: config_gen::main
  10: std::rt::lang_start::{{closure}}
  11: std::panicking::try::do_call
             at libstd/rt.rs:59
             at libstd/panicking.rs:310
  12: __rust_maybe_catch_panic
             at libpanic_unwind/lib.rs:102
  13: std::rt::lang_start_internal
             at libstd/panicking.rs:289
             at libstd/panic.rs:392
             at libstd/rt.rs:58
  14: main
  15: __libc_start_main
  16: _start