`STATUS_ACCESS_VIOLATION` when building stage1 std on Windows

[el-ev]

Summary

Could not build stage1 std on Windows.

Command used

.\x build  --stage 1 -vv std rustc rustdoc

Expected behaviour

std is compiled successfully.

Actual behaviour

Build failed on core and rustc-demangle. rustc exited with (exit code: 0xc0000005, STATUS_ACCESS_VIOLATION).

Bootstrap configuration (bootstrap.toml)

[rust]
debug = true
debuginfo-level = 1
remap-debuginfo = false

Operating system

Windows 10.0.26100 (Windows 11)

HEAD

d0835ad

Additional context

Build Log

    BuildingDid not run successfully: exit code: 0xc0000005
 "D:\\rust\\build\\x86_64-pc-windows-msvc\\stage1\\bin\\rustc.exe" "--crate-name" "core" "--edition=2024" "library\\core\\src\\lib.rs" "--error-format=json" "--json=diagnostic-rendered-ansi,artifacts,future-incompat" "--diagnostic-width=112" "--crate-type" "lib" "--emit=dep-info,metadata,link" "-C" "opt-level=3" "-C" "embed-bitcode=no" "-C" "debuginfo=1" "--warn=unexpected_cfgs" "--check-cfg" "cfg(no_fp_fmt_parse)" "--check-cfg" "cfg(feature, values(any()))" "--check-cfg" "cfg(target_has_reliable_f16)" "--check-cfg" "cfg(target_has_reliable_f16_math)" "--check-cfg" "cfg(target_has_reliable_f128)" "--check-cfg" "cfg(target_has_reliable_f128_math)" "--check-cfg" "cfg(llvm_enzyme)" "-C" "debug-assertions=on" "--check-cfg" "cfg(docsrs,test)" "--check-cfg" "cfg(feature, values(\"debug_refcell\", \"llvm_enzyme\", \"optimize_for_size\", \"panic_immediate_abort\"))" "-C" "metadata=ead27b8ba512714c" "-C" "extra-filename=-78246d07b510ab08" "--out-dir" "D:\\rust\\build\\x86_64-pc-windows-msvc\\stage1-std\\x86_64-pc-windows-msvc\\release\\deps" "--target" "x86_64-pc-windows-msvc" "-L" "dependency=D:\\rust\\build\\x86_64-pc-windows-msvc\\stage1-std\\x86_64-pc-windows-msvc\\release\\deps" "-L" "dependency=D:\\rust\\build\\x86_64-pc-windows-msvc\\stage1-std\\release\\deps" "-Csymbol-mangling-version=legacy" "-Zannotate-moves" "--check-cfg=cfg(feature,values(any()))" "-Zunstable-options" "-Zmacro-backtrace" "-Csplit-debuginfo=packed" "-Ctarget-feature=+crt-static" "-Cprefer-dynamic" "-Zinline-mir" "-Zinline-mir-preserve-debug" "-Zmir_strip_debuginfo=locals-in-tiny-functions" "-Alinker-messages" "-Cembed-bitcode=yes" "-Clto=off" "-Zunstable-options" "-Cforce-frame-pointers=non-leaf" "-Zcrate-attr=doc(html_root_url=\"https://doc.rust-lang.org/nightly/\")" "-Z" "binary-dep-depinfo" "-Wrust_2018_idioms" "-Wunused_lifetimes" "-Dwarnings" "--sysroot" "D:\\rust\\build\\x86_64-pc-windows-msvc\\stage1" "-Z" "force-unstable-if-unmarked"[=====================>     ] 15/18: core, rustc-demangle                                 

-------------
error: could not compile `core` (lib)

Caused by:
  process didn't exit successfully: `D:\rust\build\bootstrap\debug\rustc D:\rust\build\bootstrap\debug\rustc --crate-name core --edition=2024 library\core\src\lib.rs --error-format=json --json=diagnostic-rendered-ansi,artifacts,future-incompat --diagnostic-width=112 --crate-type lib --emit=dep-info,metadata,link -C opt-level=3 -C embed-bitcode=no -C debuginfo=1 --warn=unexpected_cfgs --check-cfg cfg(no_fp_fmt_parse) --check-cfg "cfg(feature, values(any()))" --check-cfg cfg(target_has_reliable_f16) --check-cfg cfg(target_has_reliable_f16_math) --check-cfg cfg(target_has_reliable_f128) --check-cfg cfg(target_has_reliable_f128_math) --check-cfg cfg(llvm_enzyme) -C debug-assertions=on --check-cfg cfg(docsrs,test) --check-cfg "cfg(feature, values(\"debug_refcell\", \"llvm_enzyme\", \"optimize_for_size\", \"panic_immediate_abort\"))" -C metadata=ead27b8ba512714c -C extra-filename=-78246d07b510ab08 --out-dir D:\rust\build\x86_64-pc-windows-msvc\stage1-std\x86_64-pc-windows-msvc\release\deps --target x86_64-pc-windows-msvc -L dependency=D:\rust\build\x86_64-pc-windows-msvc\stage1-std\x86_64-pc-windows-msvc\release\deps -L dependency=D:\rust\build\x86_64-pc-windows-msvc\stage1-std\release\deps -Csymbol-mangling-version=legacy -Zannotate-moves --check-cfg=cfg(feature,values(any())) -Zunstable-options -Zmacro-backtrace -Csplit-debuginfo=packed -Ctarget-feature=+crt-static -Cprefer-dynamic -Zinline-mir -Zinline-mir-preserve-debug -Zmir_strip_debuginfo=locals-in-tiny-functions -Alinker-messages -Cembed-bitcode=yes -Clto=off -Zunstable-options -Cforce-frame-pointers=non-leaf "-Zcrate-attr=doc(html_root_url=\"https://doc.rust-lang.org/nightly/\")" -Z binary-dep-depinfo` (exit code: 0xc0000005, STATUS_ACCESS_VIOLATION)
warning: build failed, waiting for other jobs to finish...

Did not run successfully: exit code: 0xc0000005
    Building"D:\\rust\\build\\x86_64-pc-windows-msvc\\stage1\\bin\\rustc.exe" "--crate-name" "rustc_demangle" "--edition=2015" "\\.cargo\\registry\\src\\index.crates.io-1949cf8c6b5b557f\\rustc-demangle-0.1.26\\src\\lib.rs" "--error-format=json" "--json=diagnostic-rendered-ansi,artifacts,future-incompat" "--diagnostic-width=112" "--crate-type" "lib" "--emit=dep-info,metadata,link" "-C" "opt-level=s" "-C" "embed-bitcode=no" "-C" "debug-assertions=on" "--cfg" "feature=\"core\"" "--cfg" "feature=\"rustc-dep-of-std\"" "--check-cfg" "cfg(docsrs,test)" "--check-cfg" "cfg(feature, values(\"compiler_builtins\", \"core\", \"rustc-dep-of-std\", \"std\"))" "-C" "metadata=9e62bd8a76a760d9" "-C" "extra-filename=-72b953f7834f0267" "--out-dir" "D:\\rust\\build\\x86_64-pc-windows-msvc\\stage1-std\\x86_64-pc-windows-msvc\\release\\deps" "--target" "x86_64-pc-windows-msvc" "-L" "dependency=D:\\rust\\build\\x86_64-pc-windows-msvc\\stage1-std\\x86_64-pc-windows-msvc\\release\\deps" "-L" "dependency=D:\\rust\\build\\x86_64-pc-windows-msvc\\stage1-std\\release\\deps" "--extern" "core=D:\\rust\\build\\x86_64-pc-windows-msvc\\stage1-std\\x86_64-pc-windows-msvc\\release\\deps\\librustc_std_workspace_core-d79b29c79137b360.rmeta" "--cap-lints" "allow" "-Csymbol-mangling-version=legacy" "-Zannotate-moves" "--check-cfg=cfg(feature,values(any()))" "-Zunstable-options" "-Zmacro-backtrace" "-Csplit-debuginfo=packed" "-Ctarget-feature=+crt-static" "-Cprefer-dynamic" "-Zinline-mir" "-Zinline-mir-preserve-debug" "-Zmir_strip_debuginfo=locals-in-tiny-functions" "-Alinker-messages" "-Cembed-bitcode=yes" "-Clto=off" "-Zunstable-options" "-Cforce-frame-pointers=non-leaf" "-Zcrate-attr=doc(html_root_url=\"https://doc.rust-lang.org/nightly/\")" "-Z" "binary-dep-depinfo" "-Wrust_2018_idioms" "-Wunused_lifetimes" "-Dwarnings" "--sysroot" "D:\\rust\\build\\x86_64-pc-windows-msvc\\stage1" "-Z" "force-unstable-if-unmarked"
[=======================>   ] 16/18: rustc-demangle                                              -------------   
error: could not compile `rustc-demangle` (lib)

Caused by:
  process didn't exit successfully: `D:\rust\build\bootstrap\debug\rustc D:\rust\build\bootstrap\debug\rustc --crate-name rustc_demangle --edition=2015 \.cargo\registry\src\index.crates.io-1949cf8c6b5b557f\rustc-demangle-0.1.26\src\lib.rs --error-format=json --json=diagnostic-rendered-ansi,artifacts,future-incompat --diagnostic-width=112 --crate-type lib --emit=dep-info,metadata,link -C opt-level=s -C embed-bitcode=no -C debug-assertions=on --cfg "feature=\"core\"" --cfg "feature=\"rustc-dep-of-std\"" --check-cfg cfg(docsrs,test) --check-cfg "cfg(feature, values(\"compiler_builtins\", \"core\", \"rustc-dep-of-std\", \"std\"))" -C metadata=9e62bd8a76a760d9 -C extra-filename=-72b953f7834f0267 --out-dir D:\rust\build\x86_64-pc-windows-msvc\stage1-std\x86_64-pc-windows-msvc\release\deps --target x86_64-pc-windows-msvc -L dependency=D:\rust\build\x86_64-pc-windows-msvc\stage1-std\x86_64-pc-windows-msvc\release\deps -L dependency=D:\rust\build\x86_64-pc-windows-msvc\stage1-std\release\deps --extern core=D:\rust\build\x86_64-pc-windows-msvc\stage1-std\x86_64-pc-windows-msvc\release\deps\librustc_std_workspace_core-d79b29c79137b360.rmeta --cap-lints allow -Csymbol-mangling-version=legacy -Zannotate-moves --check-cfg=cfg(feature,values(any())) -Zunstable-options -Zmacro-backtrace -Csplit-debuginfo=packed -Ctarget-feature=+crt-static -Cprefer-dynamic -Zinline-mir -Zinline-mir-preserve-debug -Zmir_strip_debuginfo=locals-in-tiny-functions -Alinker-messages -Cembed-bitcode=yes -Clto=off -Zunstable-options -Cforce-frame-pointers=non-leaf "-Zcrate-attr=doc(html_root_url=\"https://doc.rust-lang.org/nightly/\")" -Z binary-dep-depinfo` (exit code: 0xc0000005, STATUS_ACCESS_VIOLATION)
command did not execute successfully: "D:\\rust\\build\\x86_64-pc-windows-msvc\\stage0\\bin\\cargo.exe" "build" "--target" "x86_64-pc-windows-msvc" "-Zbinary-dep-depinfo" "-j" "20" "-Zroot-dir=D:\\rust" "--verbose" "--release" "-p" "std" "--features" "backtrace panic-unwind" "--manifest-path" "D:\\rust\\library/sysroot/Cargo.toml" "--message-format" "json-render-diagnostics" (failure_mode=Exit)

[Fulgen301]

Are you building with VS2026's build tools? If so, build with VS2022's - there are some mismatches with download-llvm that cause a forbidden runtime mismatch.