Panic during debuginfo processing

[bjorn3]

 lldb -- wasmtime -g rust_binary.wasm
(lldb) run
thread 'main' panicked at 'called `Option::unwrap()` on a `None` value', src/libcore/option.rs:347:21
stack backtrace:
   0: std::sys::unix::backtrace::tracing::imp::unwind_backtrace
             at src/libstd/sys/unix/backtrace/tracing/gcc_s.rs:39
   1: std::sys_common::backtrace::_print
             at src/libstd/sys_common/backtrace.rs:71
   2: std::panicking::default_hook::{{closure}}
             at src/libstd/sys_common/backtrace.rs:59
             at src/libstd/panicking.rs:197
   3: std::panicking::default_hook
             at src/libstd/panicking.rs:211
   4: std::panicking::rust_panic_with_hook
             at src/libstd/panicking.rs:474
   5: std::panicking::continue_panic_fmt
             at src/libstd/panicking.rs:381
   6: rust_begin_unwind
             at src/libstd/panicking.rs:308
   7: core::panicking::panic_fmt
             at src/libcore/panicking.rs:85
   8: core::panicking::panic
             at src/libcore/panicking.rs:49
   9: wasmtime_debug::transform::transform_dwarf
  10: wasmtime_debug::emit_debugsections_image
  11: wasmtime_jit::compiler::Compiler::compile
  12: wasmtime_jit::instantiate::RawCompiledModule::new
  13: wasmtime_jit::instantiate::instantiate
  14: wasmtime_jit::context::Context::instantiate_module
  15: wasmtime::handle_module
  16: wasmtime::main
  17: std::rt::lang_start::{{closure}}
  18: std::panicking::try::do_call
             at src/libstd/rt.rs:49
             at src/libstd/panicking.rs:293
  19: __rust_maybe_catch_panic
             at src/libpanic_unwind/lib.rs:85
  20: std::rt::lang_start_internal
             at src/libstd/panicking.rs:272
             at src/libstd/panic.rs:388
             at src/libstd/rt.rs:48
  21: main
  22: __libc_start_main
  23: _start

Unfortunately github considers the wasm file too big, even when compressed (~140MB). If anyone knows of a service to upload it, please tell me.

You may be able to reproduce it by cloning https://github.com/bjorn3/rust/tree/compile_rustc_for_wasm and following the instructions at the top of the README. (You will need to subsitute wasm32-unknown-wasi with wasm32-wasi.)

[bjorn3]

Backtrace with debuginfo:

thread 'main' panicked at 'called `Option::unwrap()` on a `None` value', src/libcore/option.rs:347:21
stack backtrace:
   0: std::sys::unix::backtrace::tracing::imp::unwind_backtrace
             at src/libstd/sys/unix/backtrace/tracing/gcc_s.rs:39
   1: std::sys_common::backtrace::_print
             at src/libstd/sys_common/backtrace.rs:71
   2: std::panicking::default_hook::{{closure}}
             at src/libstd/sys_common/backtrace.rs:59
             at src/libstd/panicking.rs:197
   3: std::panicking::default_hook
             at src/libstd/panicking.rs:211
   4: std::panicking::rust_panic_with_hook
             at src/libstd/panicking.rs:474
   5: std::panicking::continue_panic_fmt
             at src/libstd/panicking.rs:381
   6: rust_begin_unwind
             at src/libstd/panicking.rs:308
   7: core::panicking::panic_fmt
             at src/libcore/panicking.rs:85
   8: core::panicking::panic
             at src/libcore/panicking.rs:49
   9: wasmtime_debug::transform::transform_dwarf
             at /rustc/af98304b9a006e2f9a367b1f79dd7655f243c150/src/libcore/macros.rs:12
             at wasmtime-debug/src/transform.rs:548
             at wasmtime-debug/src/transform.rs:610
  10: wasmtime_debug::emit_debugsections_image
             at wasmtime-debug/src/lib.rs:64
  11: wasmtime_jit::compiler::Compiler::compile
             at wasmtime-jit/src/compiler.rs:110
  12: wasmtime_jit::instantiate::RawCompiledModule::new
             at wasmtime-jit/src/instantiate.rs:80
  13: wasmtime_jit::instantiate::instantiate
             at wasmtime-jit/src/instantiate.rs:254
  14: wasmtime_jit::context::Context::instantiate_module
             at wasmtime-jit/src/context.rs:105
             at wasmtime-jit/src/context.rs:132
  15: wasmtime::handle_module
             at src/wasmtime.rs:294
  16: wasmtime::main
             at src/wasmtime.rs:279
  17: std::rt::lang_start::{{closure}}
             at /rustc/af98304b9a006e2f9a367b1f79dd7655f243c150/src/libstd/rt.rs:64
  18: std::panicking::try::do_call
             at src/libstd/rt.rs:49
             at src/libstd/panicking.rs:293
  19: __rust_maybe_catch_panic
             at src/libpanic_unwind/lib.rs:85
  20: std::rt::lang_start_internal
             at src/libstd/panicking.rs:272
             at src/libstd/panic.rs:388
             at src/libstd/rt.rs:48
  21: main
  22: __libc_start_main
  23: _start

The unwrap at

https://github.com/CraneStation/wasmtime/blob/1c0efd03b37489247ad2ac66f0e2b54bc29a9a1f/wasmtime-debug/src/transform.rs#L548

failed.

[bjorn3]

I uploaded it to firefox send. The download link https://send.firefox.com/download/8125bf27e3560dbe/#BGQ7Qu8XiNH6EqL12DpIjg will remain valid for 100 downloads and 7 days.

[yurydelendik]

Is it still an issue?

[bjorn3]

I saw another problem:

$ lldb -- wasmtime -g rustc_binary.wasm
(lldb) run
error: failed to process main module `../../target/wasm32-wasi/release/rustc_binary.wasm`
    caused by: Debug information error: UnexpectedEof(ReaderOffsetId(11060999730))

https://send.firefox.com/download/344bba782e6da813/#yYsCDH8pDUj3GC24fYHLlQ (for own reference when needing to re-upload: mac wasmtime_crashes/issue-144-2-rustc_binary.wasm.zip)

[alexcrichton]

It looks like the most recent version of this is an error rather than a panic, so I'm going to close this as "likely fixed". If it still crops up though please feel free to resubmit a new issue! I'd recommend using gzip to compress the wasm module and upload it directly to GitHub if possible as well.

[bjorn3]

If it still crops up though please feel free to resubmit a new issue!

+1 If I try to compile rustc for wasm again and notice this bug I will submit a new issue.

I'd recommend using gzip to compress the wasm module and upload it directly to GitHub if possible as well.

It was still way too large after that last time.