$  gdb --args orz__debug_w32 encode README.md README.md.orz
GNU gdb (GDB) 7.9.1
(...)
Reading symbols from orz__debug_w32...done.
(gdb) r
Starting program: d:\progs\dev\src\orz\orz\orz__debug_w32.exe encode README.md README.md.orz
[New Thread 14228.0x11dc]
[New Thread 14228.0x2980]
[New Thread 14228.0x1cc4]
[New Thread 14228.0x450]

Program received signal SIGSEGV, Segmentation fault.
_alloca () at ../../../../../src/gcc-8.1.0/libgcc/config/i386/cygwin.S:88
88      ../../../../../src/gcc-8.1.0/libgcc/config/i386/cygwin.S: No such file or directory.
(gdb) bt
#0  _alloca () at ../../../../../src/gcc-8.1.0/libgcc/config/i386/cygwin.S:88
#1  0x0057ca13 in orz::encode::h64d6467265acc7bf (
    source=<error reading variable: Cannot access memory at address 0x6a0fc30>,
    target=<error reading variable: Cannot access memory at address 0x6a0fc38>, cfg=0x1a0fae4) at src/lib.rs:44
#2  0x004036d6 in orz::main::hc5aba79d15bc2c2c () at src/main.rs:94
#3  0x00407f0b in core::ops::function::FnOnce::call_once::hfde464d49ace8ae2 ()
    at /rustc/e092d0b6b43f2de967af0887873151bb1c0b18d3\library\core\src\ops/function.rs:248
#4  0x00402062 in std::sys_common::backtrace::__rust_begin_short_backtrace::h3b09b2cc1997b89a (
    f=0x402910 <orz::main::hc5aba79d15bc2c2c>)
    at /rustc/e092d0b6b43f2de967af0887873151bb1c0b18d3\library\std\src\sys_common/backtrace.rs:122
#5  0x00408a93 in std::rt::lang_start::_$u7b$$u7b$closure$u7d$$u7d$::he2d87c0b87bf469b ()
    at /rustc/e092d0b6b43f2de967af0887873151bb1c0b18d3\library\std\src/rt.rs:145
#6  0x0065c340 in call_once<(), (dyn core::ops::function::Fn<(), Output=i32> + core::marker::Sync + core::panic::unwind_safe::RefUnwindSafe)> () at /rustc/e092d0b6b43f2de967af0887873151bb1c0b18d3\library\core\src\ops/function.rs:280
#7  do_call<&(dyn core::ops::function::Fn<(), Output=i32> + core::marker::Sync + core::panic::unwind_safe::RefUnwindSafe), i32> () at library\std\src/panicking.rs:492
#8  try<i32, &(dyn core::ops::function::Fn<(), Output=i32> + core::marker::Sync + core::panic::unwind_safe::RefUnwindSafe)> () at library\std\src/panicking.rs:456
#9  catch_unwind<&(dyn core::ops::function::Fn<(), Output=i32> + core::marker::Sync + core::panic::unwind_safe::RefUnwindSafe), i32> () at library\std\src/panic.rs:137
#10 {closure#2} () at library\std\src/rt.rs:128
#11 do_call<std::rt::lang_start_internal::{closure_env#2}, isize> () at library\std\src/panicking.rs:492
#12 try<isize, std::rt::lang_start_internal::{closure_env#2}> () at library\std\src/panicking.rs:456
#13 catch_unwind<std::rt::lang_start_internal::{closure_env#2}, isize> () at library\std\src/panic.rs:137
#14 std::rt::lang_start_internal::h71a9cc7a00235f34 () at library\std\src/rt.rs:128
#15 0x00408a70 in std::rt::lang_start::h9847c1da96d8463b (main=0x402910 <orz::main::hc5aba79d15bc2c2c>, argc=4,
    argv=0x22e2df8) at /rustc/e092d0b6b43f2de967af0887873151bb1c0b18d3\library\std\src/rt.rs:144
#16 0x004053c3 in main ()
(gdb) l
83      in ../../../../../src/gcc-8.1.0/libgcc/config/i386/cygwin.S
(gdb)  r
The program being debugged has been started already.
Start it from the beginning? (y or n) y
Starting program: d:\progs\dev\src\orz\orz\orz__debug_w32.exe encode README.md README.md.orz
[New Thread 22192.0x4bc8]
[New Thread 22192.0x24ac]
[New Thread 22192.0x3da4]
[New Thread 22192.0xf1c]

Program received signal SIGSEGV, Segmentation fault.
_alloca () at ../../../../../src/gcc-8.1.0/libgcc/config/i386/cygwin.S:88
88      in ../../../../../src/gcc-8.1.0/libgcc/config/i386/cygwin.S
(gdb) q