Cross-compiling a static binary from GitHub Actions

[kinke]

On Friday, 1 October 2021 at 11:18:52 UTC, Vladimir Panteleev 
wrote:
> Rented an AWS EC2 ARM box today and tried it out there. The 
> std.process segfaults indeed appear to be specific to the 
> QEMU/binfmt interaction, however, exceptions still did not 
> work. I narrowed it down to `-static`, confirming your guess. 
> Seems to be an issue with unwinding?
>
> ```
>   * frame #0: 0x0000000000518180 btdu-static-aarch64`gsignal + 
> 224
>     frame #1: 0x0000000000400434 btdu-static-aarch64`abort + 244
>     frame #2: 0x000000000050e1f4 
> btdu-static-aarch64`uw_init_context_1 + 580
>     frame #3: 0x000000000050eb44 
> btdu-static-aarch64`_Unwind_Backtrace + 84
>     frame #4: 0x000000000054d214 btdu-static-aarch64`backtrace 
> + 68
>     frame #5: 0x00000000004fb524 
> btdu-static-aarch64`_D4core7runtime19defaultTraceHandlerFPvZC6object9Throwable9TraceInfo + 116
>     frame #6: 0x00000000004fcf08 
> btdu-static-aarch64`_d_createTrace + 76
>     frame #7: 0x00000000004e1a6c 
> btdu-static-aarch64`_d_throw_exception + 176
>     frame #8: 0x00000000004399cc 
> btdu-static-aarch64`_D3std9exception__T7bailOutHTC9ExceptionZQwFNaNfAyamMAxaZNn(file=(length = 39, ptr = u8"/home/ubuntu/btdu/source/btdu/subproc.d"), line=109, msg=(length = 33, ptr = u8"Unexpected subprocess termination")) at exception.d:517:9
> ```

Hmm, apparently coming from libbacktrace. IIRC, EH and backtrace 
code in druntime for Linux AArch64 doesn't really diverge from 
x64.

I guess you *could* try compiling druntime manually, defining 
`version (DRuntime_Use_Libunwind)` to use libunwind instead of 
libbacktrace. See 
https://wiki.dlang.org/Building_LDC_runtime_libraries for how to 
do that quite painlessly.