all `mipsisa*-linux` targets build failed

rustc 1.100.0-nightly (5a2be9f5f 2026-09-06)
build with -Zbuild-std
targets affected:

mipsisa32r6-unknown-linux-gnu
mipsisa32r6el-unknown-linux-gnu
mipsisa64r6-unknown-linux-gnuabi64
mipsisa64r6el-unknown-linux-gnuabi64

error content:

error: could not compile `compiler_builtins` (lib)

Caused by:
  process didn't exit successfully: `/home/runner/.rustup/toolchains/nightly-aarch64-unknown-linux-gnu/bin/rustc --crate-name compiler_builtins --edition=2024 /home/runner/.rustup/toolchains/nightly-aarch64-unknown-linux-gnu/lib/rustlib/src/rust/library/compiler-builtins/compiler-builtins/src/lib.rs --error-format=json --json=diagnostic-rendered-ansi,artifacts,future-incompat,unused-externs-silent,diagnostic-unicode --crate-type lib --emit=dep-info,metadata,link -Z embed-metadata=no -C opt-level=3 -C panic=immediate-abort -Z unstable-options -C linker-plugin-lto -C codegen-units=1 --remap-path-scope=all --remap-path-prefix=/home/runner/.rustup/toolchains/nightly-aarch64-unknown-linux-gnu/lib/rustlib/src/rust/library/compiler-builtins/compiler-builtins=/cargo/deps/compiler_builtins-0.1.160 --remap-path-prefix=/home/runner/work/Img/Img/build-dir=/cargo/build-dir --remap-path-prefix=/home/runner/.rustup/toolchains/nightly-aarch64-unknown-linux-gnu/lib/rustlib/src/rust=/rustc/5a2be9f5f075d31e3ca5526b5b029881ce441253 -Zlocation-detail=none -Ztrap-unreachable=no --cfg 'feature="arch"' --cfg 'feature="compiler-builtins"' --cfg 'feature="default"' --cfg 'feature="unmangled-names"' --check-cfg 'cfg(docsrs,test)' --check-cfg 'cfg(feature, values("arch", "c", "compiler-builtins", "default", "mem", "unmangled-names", "unstable-public-internals"))' -C metadata=29035f4b947204f3 -C extra-filename=-8d86bf15882815a3 -C rpath --out-dir /home/runner/work/Img/Img/build-dir/mipsisa64r6-unknown-linux-gnuabi64/src/build/compiler_builtins/8d86bf15882815a3/out --target mipsisa64r6-unknown-linux-gnuabi64 -C linker=mipsisa64r6-linux-gnuabi64-gcc -C strip=debuginfo -Z force-unstable-if-unmarked -L dependency=/home/runner/work/Img/Img/build-dir/src/build/compiler_builtins/8d86bf15882815a3/out --extern 'priv:core=/home/runner/work/Img/Img/build-dir/mipsisa64r6-unknown-linux-gnuabi64/src/build/core/5dab6b9f1fef9dd3/out/libcore-5dab6b9f1fef9dd3.rmeta' -Z unstable-options --cap-lints allow -Ctarget-feature=-crt-static -Csymbol-mangling-version=hashed -Coverflow-checks=no -Cforce-frame-pointers=no -Cforce-unwind-tables=no -Cno-redzone -Cdebuginfo=0 -Cstrip=symbols -Ccollapse-macro-debuginfo=y -Cpanic=immediate-abort -Zunstable-options -Zembed-metadata=no -Zexport-executable-symbols -Zno-profiler-runtime -Zlocation-detail=none -Ztrap-unreachable=no -Zplt -Zthinlto -Zdylib-lto -Zno-generate-arange-section -Zdep-info-omit-d-target -Zpolonius=next -Ztrim-diagnostic-paths -Zshare-generics -Zinline-mir-preserve-debug=n -Zmir-opt-level=4 -Zpacked-bundled-libs -Zterminal-urls -Zthreads=0 -Zstaticlib-allow-rdylib-deps -Zstaticlib-prefer-dynamic -Znext-solver=coherence -Zpanic-in-drop=abort -Zuse-sync-unwind -Zgraphviz-dark-mode -Zshell-argfiles -Zchecksum-hash-algorithm=blake3 -Zmir-strip-debuginfo=all-locals -Ztyping-mode-post-typeck-until-borrowck -Zexperimental-default-bounds -Zhigher-ranked-assumptions -Zcache-proc-macros -Zvalidate-mir=no '-Dclippy::redundant_clone' '-Dclippy::unused_io_amount' -Clink-arg=-Wl,-z,execstack -Clink-self-contained=+linker -Clinker-features=+lld -Clinker-plugin-lto -Clink-arg=-Wl,--icf=all -Clink-arg=-Wl,--relax -Clink-arg=-Wl,-z,pack-relative-relocs -Clink-arg=-Wl,--gc-sections -Clink-arg=-Wl,-z,norelro -Clink-arg=-Wl,-z,pack-relative-relocs -Clink-arg=-Wl,--as-needed -Clink-arg=-Wl,--discard-all -Clink-arg=-Wl,--build-id=none -Clink-arg=-Wl,--strip-all -Clink-arg=-Wl,--no-eh-frame-hdr -Zrelax-elf-relocations -Z binary-dep-depinfo --force-warn=unused_crate_dependencies --cfg intrinsics_enabled --cfg optimizations_enabled --cfg f16_enabled --cfg f128_enabled --check-cfg 'cfg(thumb)' --check-cfg 'cfg(thumb_1)' --check-cfg 'cfg(x86_no_sse2)' --check-cfg 'cfg(assert_no_panic)' --check-cfg 'cfg(intrinsics_enabled)' --check-cfg 'cfg(optimizations_enabled)' --check-cfg 'cfg(f16_enabled)' --check-cfg 'cfg(f128_enabled)' --check-cfg 'cfg(__ashldi3, values("optimized-c"))' --check-cfg 'cfg(__ashlsi3, values("optimized-c"))' --check-cfg 'cfg(__ashrdi3, values("optimized-c"))' --check-cfg 'cfg(__ashrsi3, values("optimized-c"))' --check-cfg 'cfg(__bswapsi2, values("optimized-c"))' --check-cfg 'cfg(__bswapdi2, values("optimized-c"))' --check-cfg 'cfg(__bswapti2, values("optimized-c"))' --check-cfg 'cfg(__divdi3, values("optimized-c"))' --check-cfg 'cfg(__divsi3, values("optimized-c"))' --check-cfg 'cfg(__divmoddi4, values("optimized-c"))' --check-cfg 'cfg(__divmodsi4, values("optimized-c"))' --check-cfg 'cfg(__divmodsi4, values("optimized-c"))' --check-cfg 'cfg(__divmodti4, values("optimized-c"))' --check-cfg 'cfg(__lshrdi3, values("optimized-c"))' --check-cfg 'cfg(__lshrsi3, values("optimized-c"))' --check-cfg 'cfg(__moddi3, values("optimized-c"))' --check-cfg 'cfg(__modsi3, values("optimized-c"))' --check-cfg 'cfg(__muldi3, values("optimized-c"))' --check-cfg 'cfg(__udivdi3, values("optimized-c"))' --check-cfg 'cfg(__udivmoddi4, values("optimized-c"))' --check-cfg 'cfg(__udivmodsi4, values("optimized-c"))' --check-cfg 'cfg(__udivsi3, values("optimized-c"))' --check-cfg 'cfg(__umoddi3, values("optimized-c"))' --check-cfg 'cfg(__umodsi3, values("optimized-c"))' --check-cfg 'cfg(__aarch64_cas1_relax, values("optimized-c"))' --check-cfg 'cfg(__aarch64_cas1_acq, values("optimized-c"))' --check-cfg 'cfg(__aarch64_cas1_rel, values("optimized-c"))' --check-cfg 'cfg(__aarch64_cas1_acq_rel, values("optimized-c"))' --check-cfg 'cfg(__aarch64_cas2_relax, values("optimized-c"))' --check-cfg 'cfg(__aarch64_cas2_acq, values("optimized-c"))' --check-cfg 'cfg(__aarch64_cas2_rel, values("optimized-c"))' --check-cfg 'cfg(__aarch64_cas2_acq_rel, values("optimized-c"))' --check-cfg 'cfg(__aarch64_cas4_relax, values("optimized-c"))' --check-cfg 'cfg(__aarch64_cas4_acq, values("optimized-c"))' --check-cfg 'cfg(__aarch64_cas4_rel, values("optimized-c"))' --check-cfg 'cfg(__aarch64_cas4_acq_rel, values("optimized-c"))' --check-cfg 'cfg(__aarch64_cas8_relax, values("optimized-c"))' --check-cfg 'cfg(__aarch64_cas8_acq, values("optimized-c"))' --check-cfg 'cfg(__aarch64_cas8_rel, values("optimized-c"))' --check-cfg 'cfg(__aarch64_cas8_acq_rel, values("optimized-c"))' --check-cfg 'cfg(__aarch64_cas16_relax, values("optimized-c"))' --check-cfg 'cfg(__aarch64_cas16_acq, values("optimized-c"))' --check-cfg 'cfg(__aarch64_cas16_rel, values("optimized-c"))' --check-cfg 'cfg(__aarch64_cas16_acq_rel, values("optimized-c"))' --check-cfg 'cfg(__aarch64_ldadd1_relax, values("optimized-c"))' --check-cfg 'cfg(__aarch64_ldadd1_acq, values("optimized-c"))' --check-cfg 'cfg(__aarch64_ldadd1_rel, values("optimized-c"))' --check-cfg 'cfg(__aarch64_ldadd1_acq_rel, values("optimized-c"))' --check-cfg 'cfg(__aarch64_ldadd2_relax, values("optimized-c"))' --check-cfg 'cfg(__aarch64_ldadd2_acq, values("optimized-c"))' --check-cfg 'cfg(__aarch64_ldadd2_rel, values("optimized-c"))' --check-cfg 'cfg(__aarch64_ldadd2_acq_rel, values("optimized-c"))' --check-cfg 'cfg(__aarch64_ldadd4_relax, values("optimized-c"))' --check-cfg 'cfg(__aarch64_ldadd4_acq, values("optimized-c"))' --check-cfg 'cfg(__aarch64_ldadd4_rel, values("optimized-c"))' --check-cfg 'cfg(__aarch64_ldadd4_acq_rel, values("optimized-c"))' --check-cfg 'cfg(__aarch64_ldadd8_relax, values("optimized-c"))' --check-cfg 'cfg(__aarch64_ldadd8_acq, values("optimized-c"))' --check-cfg 'cfg(__aarch64_ldadd8_rel, values("optimized-c"))' --check-cfg 'cfg(__aarch64_ldadd8_acq_rel, values("optimized-c"))' --check-cfg 'cfg(__aarch64_ldclr1_relax, values("optimized-c"))' --check-cfg 'cfg(__aarch64_ldclr1_acq, values("optimized-c"))' --check-cfg 'cfg(__aarch64_ldclr1_rel, values("optimized-c"))' --check-cfg 'cfg(__aarch64_ldclr1_acq_rel, values("optimized-c"))' --check-cfg 'cfg(__aarch64_ldclr2_relax, values("optimized-c"))' --check-cfg 'cfg(__aarch64_ldclr2_acq, values("optimized-c"))' --check-cfg 'cfg(__aarch64_ldclr2_rel, values("optimized-c"))' --check-cfg 'cfg(__aarch64_ldclr2_acq_rel, values("optimized-c"))' --check-cfg 'cfg(__aarch64_ldclr4_relax, values("optimized-c"))' --check-cfg 'cfg(__aarch64_ldclr4_acq, values("optimized-c"))' --check-cfg 'cfg(__aarch64_ldclr4_rel, values("optimized-c"))' --check-cfg 'cfg(__aarch64_ldclr4_acq_rel, values("optimized-c"))' --check-cfg 'cfg(__aarch64_ldclr8_relax, values("optimized-c"))' --check-cfg 'cfg(__aarch64_ldclr8_acq, values("optimized-c"))' --check-cfg 'cfg(__aarch64_ldclr8_rel, values("optimized-c"))' --check-cfg 'cfg(__aarch64_ldclr8_acq_rel, values("optimized-c"))' --check-cfg 'cfg(__aarch64_ldeor1_relax, values("optimized-c"))' --check-cfg 'cfg(__aarch64_ldeor1_acq, values("optimized-c"))' --check-cfg 'cfg(__aarch64_ldeor1_rel, values("optimized-c"))' --check-cfg 'cfg(__aarch64_ldeor1_acq_rel, values("optimized-c"))' --check-cfg 'cfg(__aarch64_ldeor2_relax, values("optimized-c"))' --check-cfg 'cfg(__aarch64_ldeor2_acq, values("optimized-c"))' --check-cfg 'cfg(__aarch64_ldeor2_rel, values("optimized-c"))' --check-cfg 'cfg(__aarch64_ldeor2_acq_rel, values("optimized-c"))' --check-cfg 'cfg(__aarch64_ldeor4_relax, values("optimized-c"))' --check-cfg 'cfg(__aarch64_ldeor4_acq, values("optimized-c"))' --check-cfg 'cfg(__aarch64_ldeor4_rel, values("optimized-c"))' --check-cfg 'cfg(__aarch64_ldeor4_acq_rel, values("optimized-c"))' --check-cfg 'cfg(__aarch64_ldeor8_relax, values("optimized-c"))' --check-cfg 'cfg(__aarch64_ldeor8_acq, values("optimized-c"))' --check-cfg 'cfg(__aarch64_ldeor8_rel, values("optimized-c"))' --check-cfg 'cfg(__aarch64_ldeor8_acq_rel, values("optimized-c"))' --check-cfg 'cfg(__aarch64_ldset1_relax, values("optimized-c"))' --check-cfg 'cfg(__aarch64_ldset1_acq, values("optimized-c"))' --check-cfg 'cfg(__aarch64_ldset1_rel, values("optimized-c"))' --check-cfg 'cfg(__aarch64_ldset1_acq_rel, values("optimized-c"))' --check-cfg 'cfg(__aarch64_ldset2_relax, values("optimized-c"))' --check-cfg 'cfg(__aarch64_ldset2_acq, values("optimized-c"))' --check-cfg 'cfg(__aarch64_ldset2_rel, values("optimized-c"))' --check-cfg 'cfg(__aarch64_ldset2_acq_rel, values("optimized-c"))' --check-cfg 'cfg(__aarch64_ldset4_relax, values("optimized-c"))' --check-cfg 'cfg(__aarch64_ldset4_acq, values("optimized-c"))' --check-cfg 'cfg(__aarch64_ldset4_rel, values("optimized-c"))' --check-cfg 'cfg(__aarch64_ldset4_acq_rel, values("optimized-c"))' --check-cfg 'cfg(__aarch64_ldset8_relax, values("optimized-c"))' --check-cfg 'cfg(__aarch64_ldset8_acq, values("optimized-c"))' --check-cfg 'cfg(__aarch64_ldset8_rel, values("optimized-c"))' --check-cfg 'cfg(__aarch64_ldset8_acq_rel, values("optimized-c"))' --check-cfg 'cfg(__aarch64_swp1_relax, values("optimized-c"))' --check-cfg 'cfg(__aarch64_swp1_acq, values("optimized-c"))' --check-cfg 'cfg(__aarch64_swp1_rel, values("optimized-c"))' --check-cfg 'cfg(__aarch64_swp1_acq_rel, values("optimized-c"))' --check-cfg 'cfg(__aarch64_swp2_relax, values("optimized-c"))' --check-cfg 'cfg(__aarch64_swp2_acq, values("optimized-c"))' --check-cfg 'cfg(__aarch64_swp2_rel, values("optimized-c"))' --check-cfg 'cfg(__aarch64_swp2_acq_rel, values("optimized-c"))' --check-cfg 'cfg(__aarch64_swp4_relax, values("optimized-c"))' --check-cfg 'cfg(__aarch64_swp4_acq, values("optimized-c"))' --check-cfg 'cfg(__aarch64_swp4_rel, values("optimized-c"))' --check-cfg 'cfg(__aarch64_swp4_acq_rel, values("optimized-c"))' --check-cfg 'cfg(__aarch64_swp8_relax, values("optimized-c"))' --check-cfg 'cfg(__aarch64_swp8_acq, values("optimized-c"))' --check-cfg 'cfg(__aarch64_swp8_rel, values("optimized-c"))' --check-cfg 'cfg(__aarch64_swp8_acq_rel, values("optimized-c"))' --check-cfg 'cfg(target_feature, values("vis3"))' --check-cfg 'cfg(mem_unaligned)' --check-cfg 'cfg(kernel_user_helpers)'` (signal: 5, SIGTRAP: trace/breakpoint trap)

Reproduce the -Zbuild-std failure for the four listed mipsisa*-linux targets, starting with library/compiler-builtins/compiler-builtins/src/lib.rs and the displayed rustc invocation. Trace why compiling compiler_builtins receives SIGTRAP, then verify that all affected targets build successfully.