compile `compiler_builtins` failed for target `hexagon-unknown-linux-musl`

[Wyvern]

rustc 1.99.0-nightly (09ee43b 2026-07-27)
target: hexagon-unknown-linux-musl
build with -Zbuild-std

error: unrecognized instruction
  ╰╴
note: instantiated into assembly here
  ╭▸ <inline asm>:3:1
  │
3 │ FUNCTION_BEGIN __hexagon_modsi3
  ╰╴━

error: unrecognized instruction
   ╰╴
note: instantiated into assembly here
   ╭▸ <inline asm>:41:1
   │
41 │ FUNCTION_END __hexagon_modsi3
   ╰╴━

error: unrecognized instruction
    ╰╴
note: instantiated into assembly here
    ╭▸ <inline asm>:888:1
    │
888 │ FUNCTION_BEGIN __hexagon_memcpy_likely_aligned_min32bytes_mult8bytes
    ╰╴━

error: unrecognized instruction
    ╰╴
note: instantiated into assembly here
    ╭▸ <inline asm>:918:1
     ╰╴━

error: unrecognized instruction
     ╰╴
note: instantiated into assembly here
     ╭▸ <inline asm>:1334:1
     │
1334 │ FUNCTION_BEGIN __hexagon_udivdi3
     ╰╴━

error: unrecognized instruction
     ╰╴
note: instantiated into assembly here
     ╭▸ <inline asm>:1378:1
     │
1378 │ FUNCTION_END __hexagon_udivdi3
     ╰╴━

error: unrecognized instruction
     ╰╴
note: instantiated into assembly here
     ╭▸ <inline asm>:1384:1
     │
1384 │ FUNCTION_BEGIN __hexagon_udivsi3
     ╰╴━

error: unrecognized instruction
     ╰╴
note: instantiated into assembly here
     ╭▸ <inline asm>:1414:1
     │
1414 │ FUNCTION_END __hexagon_udivsi3
     ╰╴━

error: unrecognized instruction
     ╰╴
note: instantiated into assembly here
     ╭▸ <inline asm>:1418:1
     │
1418 │ FUNCTION_BEGIN __hexagon_sqrtf
     ╰╴━

error: unrecognized instruction
     ╰╴
note: instantiated into assembly here
     ╭▸ <inline asm>:1462:1
     │
1462 │ FUNCTION_END __hexagon_sqrtf
     ╰╴━

error: could not compile `compiler_builtins` (lib) due to 32 previous errors

[saethlin]

cc target maintainers @androm3da @quic-mliebel

[androm3da]

@tgross35 apologies - I should remember this process but I've forgotten. If I want to promote my change from rust-lang/compiler-builtins#1241 to here, I need to submit a PR here containing the same contents as that one? Or any/all differences from compiler-builtins should come along?

[tgross35]

Sorry for the delay, there were a few other things that needed to land on both sides. The update is in #161215.

The syncs use Josh which is unfortunately kind of convoluted and fragile. We have instructions at https://github.com/rust-lang/josh-sync but usually it's easiest to just ping a maintainer :)