build target `x86_64-unknown-fuchsia` failure, linking with lib `librustc-nightly_rt.safestack.a`?

rustc 1.100.0-nightly (a69a63265 2026-09-03)
build with -Zbuild-std
error: need link librustc-nightly_rt.safestack.a lib

error: linking with `clang` failed: exit status: 1
  │
  ├ note:  "clang" "-Wl,--dynamic-list" "-Wl,/home/runner/work/Img/Img/build-dir/x86_64-unknown-fuchsia/src/build/img/78d3d93d34d61fa7/out/rustcR0URJQ/list" "-Wl,-Bstatic" "-Wl,--whole-archive" "-Wl,<sysroot>/lib/rustlib/x86_64-unknown-fuchsia/lib/librustc-nightly_rt.safestack.a" "-Wl,--no-whole-archive" "<1 object files omitted>" "-Wl,--as-needed" "/home/runner/work/Img/Img/build-dir/x86_64-unknown-fuchsia/src/build/compiler_builtins/0492f13b814cff31/out/libcompiler_builtins-0492f13b814cff31.rlib" "-Wl,-Bdynamic" "-lc" "-lfdio" "-lzircon" "-lfdio" "-lzircon" "-lc" "-lfdio" "-L" "/home/runner/work/Img/Img/build-dir/x86_64-unknown-fuchsia/src/build/img/78d3d93d34d61fa7/out/rustcR0URJQ/raw-dylibs" "-Wl,--eh-frame-hdr" "-Wl,-z,noexecstack" "-Wl,-plugin-opt=O3,-plugin-opt=mcpu=x86-64-v3" "-L" "fuchsia/arch/x64/lib" "-L" "<sysroot>/lib/rustlib/x86_64-unknown-fuchsia/lib" "-o" "/home/runner/work/Img/Img/build-dir/x86_64-unknown-fuchsia/src/build/img/78d3d93d34d61fa7/out/img" "-Wl,--gc-sections" "-pie" "-Wl,-O1" "-Wl,--strip-all" "-nodefaultlibs" "--target=x86_64--fuchsia" "--sysroot=fuchsia/arch/x64/sysroot" "-fuse-ld=lld"
  ├ note: some arguments are omitted. use `--verbose` to show all linker arguments
  ╰ note: clang: warning: argument unused during compilation: '-pie' [-Wunused-command-line-argument]
          ld.lld: error: cannot open /home/runner/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/rustlib/x86_64-unknown-fuchsia/lib/librustc-nightly_rt.safestack.a: No such file or directory
          clang: error: ld.lld command failed with exit code 1 (use -v to see invocation)

Start by reproducing the -Zbuild-std build for x86_64-unknown-fuchsia and inspect the linker invocation shown in the report. Trace how the nightly sysroot is selected and where librustc-nightly_rt.safestack.a is expected under lib/rustlib/x86_64-unknown-fuchsia/lib; done means the target links successfully without the missing-library error.