Unsupported image format caused veloren-voxygen to panic and exit

fedora 31, cloned/built the veloren repos yesterday. nightly-2019-12-11

I believe the error that caused the panic and exit was this:

thread 'main' panicked at 'called `Result::unwrap()` on an `Err` value: UnsupportedError("Unsupported image format")', src/libcore/result.rs:1189:5

I'm unfamiliar with the code, but I think the error is somewhere related to here:

  14:     0x557cf90fc52b - <image::dynimage::DynamicImage as veloren_common::assets::Asset>::parse::h0a4ad4d8b7804c56

Placing more debug diagnostics here could help interpret what the error means exactly:

  13:     0x557cf9301867 - core::result::unwrap_failed::hc89b3c46a991cd8c
                               at src/libcore/result.rs:1189

Note there another issue mentioned with alsa, but it's unrelated and doesn't cause the exit.

Here is the entire full backtrace:

 $ RUST_BACKTRACE=full ./veloren-voxygen 
ALSA lib pcm_route.c:869:(find_matching_chmap) Found no matching channel map
ALSA lib pcm_route.c:869:(find_matching_chmap) Found no matching channel map
ALSA lib pcm_route.c:869:(find_matching_chmap) Found no matching channel map
ALSA lib pcm_route.c:869:(find_matching_chmap) Found no matching channel map
ALSA lib pcm_route.c:869:(find_matching_chmap) Found no matching channel map
ALSA lib pcm_route.c:869:(find_matching_chmap) Found no matching channel map
ALSA lib pcm_route.c:869:(find_matching_chmap) Found no matching channel map
ALSA lib pcm_route.c:869:(find_matching_chmap) Found no matching channel map
ALSA lib pcm_route.c:869:(find_matching_chmap) Found no matching channel map
ALSA lib pcm_route.c:869:(find_matching_chmap) Found no matching channel map
ALSA lib pcm_route.c:869:(find_matching_chmap) Found no matching channel map
ALSA lib pcm_route.c:869:(find_matching_chmap) Found no matching channel map
ALSA lib pcm_route.c:869:(find_matching_chmap) Found no matching channel map
ALSA lib pcm_route.c:869:(find_matching_chmap) Found no matching channel map
ALSA lib pcm_route.c:869:(find_matching_chmap) Found no matching channel map
ALSA lib pcm_route.c:869:(find_matching_chmap) Found no matching channel map
ALSA lib pcm_route.c:869:(find_matching_chmap) Found no matching channel map
ALSA lib pcm_route.c:869:(find_matching_chmap) Found no matching channel map
ALSA lib pcm_route.c:869:(find_matching_chmap) Found no matching channel map
ALSA lib pcm_route.c:869:(find_matching_chmap) Found no matching channel map
ALSA lib pcm_route.c:869:(find_matching_chmap) Found no matching channel map
ALSA lib pcm_route.c:869:(find_matching_chmap) Found no matching channel map
ALSA lib pcm_route.c:869:(find_matching_chmap) Found no matching channel map
ALSA lib pcm_route.c:869:(find_matching_chmap) Found no matching channel map
thread 'main' panicked at 'called `Result::unwrap()` on an `Err` value: UnsupportedError("Unsupported image format")', src/libcore/result.rs:1189:5
stack backtrace:
   0:     0x557cf92e0f94 - backtrace::backtrace::libunwind::trace::h0b738e58e75745ca
                               at /cargo/registry/src/github.com-1ecc6299db9ec823/backtrace-0.3.40/src/backtrace/libunwind.rs:88
   1:     0x557cf92e0f94 - backtrace::backtrace::trace_unsynchronized::h8a8fb2cd1b8a2b77
                               at /cargo/registry/src/github.com-1ecc6299db9ec823/backtrace-0.3.40/src/backtrace/mod.rs:66
   2:     0x557cf92e0f94 - std::sys_common::backtrace::_print_fmt::h3b7c5cb88cb9285f
                               at src/libstd/sys_common/backtrace.rs:84
   3:     0x557cf92e0f94 - <std::sys_common::backtrace::_print::DisplayBacktrace as core::fmt::Display>::fmt::he931c72117f7927e
                               at src/libstd/sys_common/backtrace.rs:61
   4:     0x557cf930597c - core::fmt::write::hbefb2eecb2cf504f
                               at src/libcore/fmt/mod.rs:1025
   5:     0x557cf92dafc7 - std::io::Write::write_fmt::he4add739aef71fff
                               at src/libstd/io/mod.rs:1426
   6:     0x557cf92e336e - std::sys_common::backtrace::_print::h46691af752cd6693
                               at src/libstd/sys_common/backtrace.rs:65
   7:     0x557cf92e336e - std::sys_common::backtrace::print::h001c0388a605216e
                               at src/libstd/sys_common/backtrace.rs:50
   8:     0x557cf92e336e - std::panicking::default_hook::{{closure}}::h73c204c4c23f8579
                               at src/libstd/panicking.rs:193
   9:     0x557cf92e3061 - std::panicking::default_hook::ha09a3f400c303793
                               at src/libstd/panicking.rs:210
  10:     0x557cf92e3a4b - std::panicking::rust_panic_with_hook::hc4e8bece1c2128d1
                               at src/libstd/panicking.rs:471
  11:     0x557cf92e35fe - rust_begin_unwind
                               at src/libstd/panicking.rs:375
  12:     0x557cf930176e - core::panicking::panic_fmt::h3f2d4e49be87bb2d
                               at src/libcore/panicking.rs:84
  13:     0x557cf9301867 - core::result::unwrap_failed::hc89b3c46a991cd8c
                               at src/libcore/result.rs:1189
  14:     0x557cf90fc52b - <image::dynimage::DynamicImage as veloren_common::assets::Asset>::parse::h0a4ad4d8b7804c56
  15:     0x557cf8bda27e - veloren_common::assets::load::hf31b7a8fe3a4f4b0
  16:     0x557cf8af6fad - veloren_voxygen::render::renderer::Renderer::new::h4efb2b4bc2ecfe36
  17:     0x557cf8b2527f - veloren_voxygen::window::Window::new::h22cb644e59592950
  18:     0x557cf8b7c659 - veloren_voxygen::main::h6c23bb3c06d8130a
  19:     0x557cf8ad1d83 - std::rt::lang_start::{{closure}}::h4e205e9b67b42273
Aborted (core dumped)