CLI can hang on panic

[kkartaltepe]

It seems that when parsing particular files the cli can hang after emitting a panic message like:

20:58:16 [ERROR] A panic occurred at src/utils.rs:202: called `Option::unwrap()` on a `None` value

When parsing files from the kde flatpak debug packages, of note ./packages//flatpak/runtime/org.kde.Sdk.Debug/x86_64/6.5/faf848ff0eca5e44fa6024276027b7ff07b9495e86f4d1c4f359e400084730c7/files/dwz/components/systemd-base.bst/x86_64-unknown-linux-gnu

The hung process has two threads with the following stacks:

#0  0x00007df3ffca5ebe in ?? () from target:/usr/lib/libc.so.6
#1  0x00007df3ffcab0e3 in ?? () from target:/usr/lib/libc.so.6
#2  0x000064454e777ced in std::sys::unix::thread::Thread::join ()
#3  0x000064454e1e4e15 in std::thread::JoinInner<T>::join ()
#4  0x000064454e20ce9b in dump_syms::dumper::several_files ()
#5  0x000064454e1a15b7 in dump_syms::main ()
#6  0x000064454e1a96e3 in std::sys_common::backtrace::__rust_begin_short_backtrace ()
#7  0x000064454e1a5e59 in std::rt::lang_start::{{closure}} ()
#8  0x000064454e767fcd in std::rt::lang_start_internal ()
#9  0x000064454e1a5e4e in std::rt::lang_start ()
#10 0x00007df3ffc43cd0 in ?? () from target:/usr/lib/libc.so.6
#11 0x00007df3ffc43d8a in __libc_start_main () from target:/usr/lib/libc.so.6
#12 0x000064454e1999f5 in _start ()

#0  0x00007df3ffd2488d in syscall () from target:/usr/lib/libc.so.6
#1  0x000064454e768614 in std::thread::park ()
#2  0x000064454e1ee996 in crossbeam_channel::context::Context::wait_until ()
#3  0x000064454e1eef8f in crossbeam_channel::flavors::array::Channel<T>::recv::{{closure}} ()
#4  0x000064454e1eed1d in crossbeam_channel::flavors::array::Channel<T>::recv ()
#5  0x000064454e1cb72a in crossbeam_channel::channel::Receiver<T>::recv ()
#6  0x000064454e20a7d2 in dump_syms::dumper::consumer ()
#7  0x000064454e1f5b2f in std::sys_common::backtrace::__rust_begin_short_backtrace ()
#8  0x000064454e1e575e in core::ops::function::FnOnce::call_once{{vtable.shim}} ()
#9  0x000064454e777bc5 in std::sys::unix::thread::Thread::new::thread_start ()
#10 0x00007df3ffca955a in ?? () from target:/usr/lib/libc.so.6
#11 0x00007df3ffd26a3c in ?? () from target:/usr/lib/libc.so.6

This was tested using a package installed via cargo an an up to date archlinux machine:

dump_syms v2.2.2 (https://github.com/mozilla/dump_syms.git#53341ef5):
    dump_syms