rust 1.90.0 on big-endian aarch64 fails with "internal error: entered unreachable code: found `99`"

[he32]

As mentioned in issue #145230, rust 1.90.0 can now be cross-built for the aarch64_be-unknown-netbsd target.

However, trying to use the result to build e.g. dua-cli (ref. https://github.com/Byron/dua-cli/), fails on the first invocation of the rust compiler with

thread 'main' panicked at /usr/pkgsrc/wip/rust190/work/rustc-1.90.0-src/vendor/toml_parser-1.0.1/src/lexer/mod.rs:468:21:
internal error: entered unreachable code: found `99`

Stack backtrace included below.

I expected to see this happen: I expected the build to complete.

Instead, this happened: The build bombed out on the first rustc invocation, ref. the above.

It might be relevant to ask if anyone else have had success in getting 1.90.0 to run on big-endian aarch64?

Meta

rustc --version --verbose:

rustc 1.90.0 (1159e78c4 2025-09-14) (built from a source tarball)
binary: rustc
commit-hash: 1159e78c4747b02ef996e55082b704c09b970588
commit-date: 2025-09-14
host: aarch64_be-unknown-netbsd
release: 1.90.0
LLVM version: 20.1.8

Backtrace

stack backtrace:
   0: _RNvCsugZpHxZGsu_7___rustc17rust_begin_unwindanon.fd94
   1: _ZN4core9panicking9panic_fmt17hb9275d2
   2: _RNvXs_NtCsb5oOwRtDML6_11toml_parser5lexerNtB4_5LexerNtNtNtNtCsaGn0L8hLYmQ_4core4iter6traits8iterator8Iterato
   3: _RNvMNtCsb5oOwRtDML6_11toml_parser5lexerNtB2_5
   4: _RNvNtNtCs7B6iYw67CeI_4toml2de6parser14pars
   5: _RNvMNtNtNtCs7B6iYw67CeI_4toml2de6parser7detableINtNtB8_3map3MapINtNtCsaNdGJI7j6KT_13serde_spanned7spanned7SpannedINtNtCskSGo7JFSDiU_5alloc6borrow3CoweEEIB10_NtNtB4_7devalue7DeValueEE5par
   6: _RINvNtCs7B6iYw67CeI_4toml2de8from_strINtNtB4_3map3MapNtNtCskSGo7JFSDiU_5alloc6string6StringNtNtB4_5value5Valu
   7: _RNvMNtNtCsf3ag69SxtWv_5cargo4util7contextNtB2_13GlobalContext10__load_file_RNvMNtNt
   8: _RNCNvMNtNtCsf3ag69SxtWv_5cargo4util7contextNtB4_13GlobalContext16load_values_from0B8_G
   9: _RNvMNtNtCsf3ag69SxtWv_5cargo4util7contextNtB2_13GlobalContext16load_value
  10: _RNvMNtNtCsf3ag69SxtWv_5cargo4util7contextNtB2_13Global
  11: _RNvMNtNtCsf3ag69SxtWv_5cargo4util7contextNtB2_13GlobalContext9get_tab
  12: _RNvMs_NtNtNtCsf3ag69SxtWv_5cargo4util7context2deNtB4_15ConfigMapAccess10new_struct_RNvXs19_
  13: _RINvXNtNtNtCsf3ag69SxtWv_5cargo4util7context2deNtB3_12DeserializerNtNtCs29757SMGbCR_5serde2de12Deserializer18deserialize_structNtNvXNvB5_sa_1__NtB5_10TermConfigNtB14_11Deserialize11deserialize9___VisitorECs6mSjQhQU0bZ_5cargo_RINv
  14: _RNvNtCs6mSjQhQU0bZ_5cargo3cli3cli_RNvN
  15: _RNvNtCs6mSjQhQU0bZ_5
  16: _RNvCs6mSjQhQU0bZ_5cargo4mainanon.9425c208
note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.

(Hm, these are "mangled" names, how to un-mangle? It doesn't look like c++filt does the job.)

[lukaslueg]

The error points here, maybe you want to transfer this issue to the toml project

[he32]

The error points here, maybe you want to transfer this issue to the toml project

While the error message comes from where you indicate, I'm not sure that points to the root cause of this issue. It's still early in my testing cycle for 1.90.0, but the same code has been built and works nicely natively on x86_64-unknown-netbsd, so I hesitate to point to the toml crate for the root cause. Hence my question whether this code has been successfully run on other big-endian aarch64 targets.

Just for the record, rust 1.88.0 worked on this target, and on that platform I could even natively build rust 1.88.0, both with the bundled LLVM and with an external LLVM (19.1.7).