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Add MaybeDangling to core #149775

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@WaffleLapkin WaffleLapkin commented Dec 8, 2025

This is the library part of adding MaybeDangling. Note that it doesn't actually do anything described in its docs (yet), I'll make a separate PR for that.

Tracking issue: #118166.

r? libs
cc @RalfJung

@rustbot rustbot added S-waiting-on-author Status: This is awaiting some action (such as code changes or more information) from the author. T-compiler Relevant to the compiler team, which will review and decide on the PR/issue. T-libs Relevant to the library team, which will review and decide on the PR/issue. labels Dec 8, 2025
@WaffleLapkin WaffleLapkin marked this pull request as ready for review December 8, 2025 15:49
@rustbot rustbot added S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. and removed S-waiting-on-author Status: This is awaiting some action (such as code changes or more information) from the author. labels Dec 8, 2025
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rustbot commented Dec 10, 2025

The Miri subtree was changed

cc @rust-lang/miri

RalfJung
RalfJung reviewed Dec 13, 2025
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Thanks for working on this :-)

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@rustbot rustbot added has-merge-commits PR has merge commits, merge with caution. S-waiting-on-author Status: This is awaiting some action (such as code changes or more information) from the author. labels Dec 13, 2025
@WaffleLapkin WaffleLapkin force-pushed the core-mem-maybe-dangling branch from c7db108 to 95eee60 Compare December 13, 2025 13:16
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rustbot commented Dec 13, 2025

This PR was rebased onto a different main commit. Here's a range-diff highlighting what actually changed.

Rebasing is a normal part of keeping PRs up to date, so no action is needed—this note is just to help reviewers.

@rustbot rustbot removed S-waiting-on-author Status: This is awaiting some action (such as code changes or more information) from the author. has-merge-commits PR has merge commits, merge with caution. labels Dec 13, 2025
Mark-Simulacrum
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r=me in general with commits squashed, possibly comments addressed (happy to leave specifics up to you)

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library/core/src/mem/maybe_dangling.rs Outdated
///
/// Even though the `Box`e's destructor is not run (and thus we don't have a double free bug), this
/// code is still UB. This is because when moving `boxed` into `forget`, its validity invariants
/// are asserted, causing UB since the `Box` is dangling.
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Maybe worth clarifying, e.g., "The safety comment is as such wrong, as moving the boxed variable as part of the call is a use"?

library/core/src/mem/maybe_dangling.rs Outdated
/// **not** dangling -- functions like [`as_ref`] and [`into_inner`] are safe. It is not sound to
/// return a dangling reference in a `MaybeDangling` to safe code. However, it *is* sound
/// to hold such values internally inside your code -- and there's no way to do that without
/// this type.
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It sounds like there are alternatives to this type, though, right? Is it worth saying something about ManuallyDrop or some other construct that's already stable?

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Hm... yeah fair, some other types will use this type and thus get the same effect; in particular, ManuallyDrop.

library/core/src/mem/maybe_dangling.rs
/// (and [boxes]) still must be aligned and non-null.
///
/// Additionally note that safe code can still assume that the inner value in a `MaybeDangling` is
/// **not** dangling -- functions like [`as_ref`] and [`into_inner`] are safe. It is not sound to
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How do we deal with the implicit Drop for the inner type? Should callers who place e.g. a dangling Box inside just be careful to call forget rather than letting it Drop?

library/core/src/mem/maybe_dangling.rs

use crate::{mem, ptr};

/// Allows wrapped [references] and [boxes] to dangle.
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Can we add a "Not yet actually implemented" or perhaps make maybe_dangling an incomplete lang feature? I worry a bit that as of this PR, from what I can tell, this is UB to use as documented, right? Since the compiler bits aren't there yet.

WaffleLapkin and others added 4 commits December 17, 2025 22:26
@WaffleLapkin @RalfJung
add MaybeDangling to core
4ea5cac 
Co-authored-by: Ralf Jung <[email protected]>
@WaffleLapkin
use MaybeDangling in ManuallyDrop
722e310
@WaffleLapkin
fixup BTreeMap gdb provider
7035e9f 
Now that `MaybeUninit` contains `ManuallyDrop` which contains
`MaybeDangling` (tbc this is the addition), we need to unwrap one more
layer
@WaffleLapkin
bless a mir-opt and a miri tests
25476d8
@WaffleLapkin WaffleLapkin force-pushed the core-mem-maybe-dangling branch from 95eee60 to 25476d8 Compare December 17, 2025 21:28
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WaffleLapkin commented Dec 17, 2025

I think I've addressed all the review comments.
@bors r=Mark-Simulacrum

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bors commented Dec 17, 2025

📌 Commit 25476d8 has been approved by Mark-Simulacrum

It is now in the queue for this repository.

@bors bors added S-waiting-on-bors Status: Waiting on bors to run and complete tests. Bors will change the label on completion. and removed S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. labels Dec 17, 2025
bors added a commit that referenced this pull request Dec 17, 2025
@bors
Auto merge of #149775 - WaffleLapkin:core-mem-maybe-dangling, r=Mark-…
3d0287a 
…Simulacrum

Add `MaybeDangling` to `core`

This is the library part of adding `MaybeDangling`. Note that it doesn't actually do anything described in its docs (yet), I'll make a separate PR for that.

Tracking issue: #118166.

r? libs
cc `@RalfJung`
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bors commented Dec 17, 2025

⌛ Testing commit 25476d8 with merge 3d0287a...

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rust-log-analyzer commented Dec 17, 2025

The job aarch64-msvc-1 failed! Check out the build log: (web) (plain enhanced) (plain)

Click to see the possible cause of the failure (guessed by this bot) 
failures:

---- [debuginfo-cdb] tests\debuginfo\marker-types.rs stdout ----

error: check directive(s) from `C:\a\rust\rust\tests\debuginfo\marker-types.rs` not found in debugger output. errors:
    (marker-types.rs:14) `manuallydrop     : 12345 [Type: core::mem::manually_drop::ManuallyDrop<i32>]`
the following subset of check directive(s) was found successfully:
    (marker-types.rs:9) `nonnull          : NonNull(0x7ff6c5a742f0: 0xc) [Type: core::ptr::non_null::NonNull<u32>]`
    (marker-types.rs:10) `    [<Raw View>]     [Type: core::ptr::non_null::NonNull<u32>]`
    (marker-types.rs:11) `    0xc [Type: unsigned int]`
    (marker-types.rs:15) `    [<Raw View>]     [Type: core::mem::manually_drop::ManuallyDrop<i32>]`
    (marker-types.rs:18) `pin              : Pin(0xe661aff5a8: "this") [Type: core::pin::Pin<ref_mut$<alloc::string::String> >]`
    (marker-types.rs:19) `    [<Raw View>]     [Type: core::pin::Pin<ref_mut$<alloc::string::String> >]`
    (marker-types.rs:20) `    [len]            : 0x4 [Type: unsigned __int64]`
    (marker-types.rs:21) `    [capacity]       : 0x4 [Type: unsigned __int64]`
    (marker-types.rs:22) `    [chars]          : "this"`
    (marker-types.rs:25) `unique           : Unique(0xe661aff5c0: (0x2a, 4321)) [Type: core::ptr::unique::Unique<tuple$<u64,i32> >]`
    (marker-types.rs:26) `    [<Raw View>]     [Type: core::ptr::unique::Unique<tuple$<u64,i32> >]`
    (marker-types.rs:27) `    [0]              : 0x2a [Type: unsigned __int64]`
    (marker-types.rs:28) `    [1]              : 4321 [Type: int]`
status: exit code: 0
command: PATH="C:\a\rust\rust\build\aarch64-pc-windows-msvc\stage2\lib\rustlib\aarch64-pc-windows-msvc\lib;C:\Program Files (x86)\Windows Kits\10\bin\arm64;C:\Program Files (x86)\Windows Kits\10\bin\10.0.26100.0\arm64;C:\Program Files\Microsoft Visual Studio\2022\Enterprise\VC\Tools\MSVC\14.44.35207\bin\HostARM64\arm64;C:\Program Files\Microsoft Visual Studio\2022\Enterprise\VC\Tools\MSVC\14.44.35207\bin\HostARM64\arm64;C:\a\rust\rust\build\aarch64-pc-windows-msvc\bootstrap-tools\aarch64-pc-windows-msvc\release\deps;C:\Program Files\Git\clangarm64\bin;C:\Program Files\Git\usr\bin;C:\Users\runneradmin\bin;C:\a\rust\rust\ninja;C:\a\rust\rust\citools\clang-rust\bin;C:\a\rust\rust\sccache;C:\aliyun-cli;C:\vcpkg;C:\Program Files (x86)\NSIS;C:\Program Files\Mercurial;C:\hostedtoolcache\windows\stack\3.7.1\x64;C:\mingw64\bin;C:\Program Files\dotnet;C:\Program Files\MySQL\MySQL Server 8.0\bin;C:\Program Files (x86)\R\R-4.5.1\bin\x64;C:\SeleniumWebDrivers\GeckoDriver;C:\SeleniumWebDrivers\EdgeDriver;C:\SeleniumWebDrivers\ChromeDriver;C:\Program Files (x86)\sbt\bin;C:\Program Files (x86)\GitHub CLI;C:\Program Files\Git\usr\bin;C:\Program Files (x86)\pipx_bin;C:\npm\prefix;C:\hostedtoolcache\windows\go\1.24.9\arm64\bin;C:\hostedtoolcache\windows\Python\3.12.10\arm64\Scripts;C:\hostedtoolcache\windows\Python\3.12.10\arm64;C:\hostedtoolcache\windows\Ruby\3.4.7\aarch64\bin;C:\Program Files\OpenSSL\bin;C:\tools\kotlinc\bin;C:\hostedtoolcache\windows\Java_Temurin-Hotspot_jdk\21.0.8-9.0\aarch64\bin;C:\Program Files (x86)\ImageMagick-7.1.2-Q16-HDRI;C:\Program Files\Microsoft SDKs\Azure\CLI2\wbin;C:\ProgramData\kind;C:\ProgramData\Chocolatey\bin;C:\Windows\system32;C:\Windows;C:\Windows\System32\Wbem;C:\Windows\System32\WindowsPowerShell\v1.0;C:\Windows\System32\OpenSSH;C:\Program Files\PowerShell\7;C:\Program Files\Microsoft\Web Platform Installer;C:\Program Files\Microsoft SQL Server\Client SDK\ODBC\170\Tools\Binn;C:\Program Files\Microsoft SQL Server\150\Tools\Binn;C:\Program Files\dotnet;C:\Program Files (x86)\Windows Kits\10\Windows Performance Toolkit;C:\Program Files\Microsoft SQL Server\130\DTS\Binn;C:\Program Files\Microsoft SQL Server\140\DTS\Binn;C:\Program Files\Microsoft SQL Server\150\DTS\Binn;C:\Program Files\Microsoft SQL Server\160\DTS\Binn;C:\Program Files\Microsoft SQL Server\170\DTS\Binn;C:\Strawberry\c\bin;C:\Strawberry\perl\site\bin;C:\Strawberry\perl\bin;C:\ProgramData\chocolatey\lib\pulumi\tools\Pulumi\bin;C:\Program Files\CMake\bin;C:\Tools\Ninja;C:\ProgramData\chocolatey\lib\maven\apache-maven-3.9.11\bin;C:\Program Files\LLVM\bin;C:\Program Files\nodejs;C:\Program Files\Git\cmd;C:\Program Files\Git\clangarm64\bin;C:\Program Files\Git\usr\bin;C:\Program Files\GitHub CLI;C:\tools\php;C:\Program Files (x86)\sbt\bin;C:\Program Files\Amazon\AWSCLIV2;C:\Program Files\Amazon\SessionManagerPlugin\bin;C:\Program Files\Amazon\AWSSAMCLI\bin;C:\Program Files\Microsoft SQL Server\130\Tools\Binn;C:\Users\runneradmin\.dotnet\tools;C:\Users\runneradmin\.cargo\bin;C:\Users\runneradmin\AppData\Local\Microsoft\WindowsApps" "C:\\Program Files (x86)\\Windows Kits\\10\\Debuggers\\arm64\\cdb.exe" "-lines" "-cf" "C:\\a\\rust\\rust\\build\\aarch64-pc-windows-msvc\\test\\debuginfo\\marker-types.cdb\\marker-types.debugger.script" "C:\\a\\rust\\rust\\build\\aarch64-pc-windows-msvc\\test\\debuginfo\\marker-types.cdb\\a.exe"
--- stdout -------------------------------

************* Preparing the environment for Debugger Extensions Gallery repositories **************
   ExtensionRepository : Implicit
   UseExperimentalFeatureForNugetShare : true
   AllowNugetExeUpdate : true
   NonInteractiveNuget : true
   AllowNugetMSCredentialProviderInstall : true
   AllowParallelInitializationOfLocalRepositories : true

   EnableRedirectToV8JsProvider : false

   -- Configuring repositories
      ----> Repository : LocalInstalled, Enabled: true
      ----> Repository : UserExtensions, Enabled: true

>>>>>>>>>>>>> Preparing the environment for Debugger Extensions Gallery repositories completed, duration 0.000 seconds

************* Waiting for Debugger Extensions Gallery to Initialize **************

>>>>>>>>>>>>> Waiting for Debugger Extensions Gallery to Initialize completed, duration 0.015 seconds
   ----> Repository : UserExtensions, Enabled: true, Packages count: 0
   ----> Repository : LocalInstalled, Enabled: true, Packages count: 27

Microsoft (R) Windows Debugger Version 10.0.26100.1 ARM64
Copyright (c) Microsoft Corporation. All rights reserved.

CommandLine: C:\a\rust\rust\build\aarch64-pc-windows-msvc\test\debuginfo\marker-types.cdb\a.exe

************* Path validation summary **************
Response                         Time (ms)     Location
Deferred                                       srv*
Symbol search path is: srv*
Executable search path is: 
ModLoad: 00007ff6`c5a70000 00007ff6`c5a79000   a.exe   
ModLoad: 00007ffb`a0ad0000 00007ffb`a0f02000   ntdll.dll
ModLoad: 00007ffb`9f420000 00007ffb`9f588000   C:\Windows\System32\KERNEL32.DLL
ModLoad: 00007ffb`9bc60000 00007ffb`9c31b000   C:\Windows\System32\KERNELBASE.dll
ModLoad: 00007ffb`9b840000 00007ffb`9b946000   C:\Windows\SYSTEM32\apphelp.dll
ModLoad: 00007ffb`9c8e0000 00007ffb`9cb08000   C:\Windows\System32\ucrtbase.dll
ModLoad: 00007ffb`85850000 00007ffb`85884000   C:\Windows\SYSTEM32\VCRUNTIME140.dll
ModLoad: 00007ffb`4e7a0000 00007ffb`4f19b000   C:\a\rust\rust\build\aarch64-pc-windows-msvc\stage2\lib\rustlib\aarch64-pc-windows-msvc\lib\std-10684b3e71b059f9.dll
ModLoad: 00007ffb`9f590000 00007ffb`9f653000   C:\Windows\System32\WS2_32.dll
ModLoad: 00007ffb`9a490000 00007ffb`9a4e0000   C:\Windows\SYSTEM32\USERENV.dll
ModLoad: 00007ffb`9dc20000 00007ffb`9de23000   C:\Windows\System32\RPCRT4.dll
ModLoad: 00007ffb`9c390000 00007ffb`9c470000   C:\Windows\System32\bcryptprimitives.dll
(bb8.a4c): Break instruction exception - code 80000003 (first chance)
ntdll!LdrpDoDebuggerBreak+0x34:
00007ffb`a0c2c184 d43e0000 brk         #0xF000
0:000> version
Windows 10 Version 26200 MP (4 procs) Free ARM 64-bit (AArch64)
Product: WinNt, suite: SingleUserTS
Edition build lab: 26100.1.arm64fre.ge_release.240331-1435
Build layer: DesktopEditions -> 26100.1.arm64fre.ge_release.240331-1435
Build layer: OnecoreUAP -> 26100.1.arm64fre.ge_release.240331-1435
Build layer: ShellCommon -> 26100.6899.arm64fre.ge_release_svc_prod1.251010-1022
Build layer: OSClient   -> 26100.6899.arm64fre.ge_release_svc_prod1.251010-1022
Debug session time: Wed Dec 17 23:29:06.453 2025 (UTC + 0:00)
System Uptime: 0 days 2:20:52.588
Process Uptime: 0 days 0:00:00.054
  Kernel time: 0 days 0:00:00.000
  User time: 0 days 0:00:00.015
Live user mode: <Local>

Microsoft (R) Windows Debugger Version 10.0.26100.1 ARM64
Copyright (c) Microsoft Corporation. All rights reserved.

command line: '"C:\Program Files (x86)\Windows Kits\10\Debuggers\arm64\cdb.exe" -lines -cf C:\a\rust\rust\build\aarch64-pc-windows-msvc\test\debuginfo\marker-types.cdb\marker-types.debugger.script C:\a\rust\rust\build\aarch64-pc-windows-msvc\test\debuginfo\marker-types.cdb\a.exe'  Debugger Process 0x2824 
dbgeng:  image 10.0.26100.1, 
        [path: C:\Program Files (x86)\Windows Kits\10\Debuggers\arm64\dbgeng.dll]
dbghelp: image 10.0.26100.4654, 
        [path: C:\Program Files (x86)\Windows Kits\10\Debuggers\arm64\dbghelp.dll]
        DIA version: 33140
Extension DLL search Path:
    C:\Program Files (x86)\Windows Kits\10\Debuggers\arm64\WINXP;C:\Program Files (x86)\Windows Kits\10\Debuggers\arm64\winext;C:\Program Files (x86)\Windows Kits\10\Debuggers\arm64\winext\arcade;C:\Program Files (x86)\Windows Kits\10\Debuggers\arm64\pri;C:\Program Files (x86)\Windows Kits\10\Debuggers\arm64;C:\Users\runneradmin\AppData\Local\Dbg\EngineExtensions;C:\Program Files (x86)\Windows Kits\10\Debuggers\arm64;C:\a\rust\rust\build\aarch64-pc-windows-msvc\stage2\lib\rustlib\aarch64-pc-windows-msvc\lib;C:\Program Files (x86)\Windows Kits\10\bin\arm64;C:\Program Files (x86)\Windows Kits\10\bin\10.0.26100.0\arm64;C:\Program Files\Microsoft Visual Studio\2022\Enterprise\VC\Tools\MSVC\14.44.35207\bin\HostARM64\arm64;C:\Program Files\Microsoft Visual Studio\2022\Enterprise\VC\Tools\MSVC\14.44.35207\bin\HostARM64\arm64;C:\a\rust\rust\build\aarch64-pc-windows-msvc\bootstrap-tools\aarch64-pc-windows-msvc\release\deps;C:\Program Files\Git\clangarm64\bin;C:\Program Files\Git\usr\bin;C:\Users\runneradmin\bin;C:\a\rust\rust\ninja;C:\a\rust\rust\citools\clang-rust\bin;C:\a\rust\rust\sccache;C:\aliyun-cli;C:\vcpkg;C:\Program Files (x86)\NSIS;C:\Program Files\Mercurial;C:\hostedtoolcache\windows\stack\3.7.1\x64;C:\mingw64\bin;C:\Program Files\dotnet;C:\Program Files\MySQL\MySQL Server 8.0\bin;C:\Program Files (x86)\R\R-4.5.1\bin\x64;C:\SeleniumWebDrivers\GeckoDriver;C:\SeleniumWebDrivers\EdgeDriver;C:\SeleniumWebDrivers\ChromeDriver;C:\Program Files (x86)\sbt\bin;C:\Program Files (x86)\GitHub CLI;C:\Program Files\Git\usr\bin;C:\Program Files (x86)\pipx_bin;C:\npm\prefix;C:\hostedtoolcache\windows\go\1.24.9\arm64\bin;C:\hostedtoolcache\windows\Python\3.12.10\arm64\Scripts;C:\hostedtoolcache\windows\Python\3.12.10\arm64;C:\hostedtoolcache\windows\Ruby\3.4.7\aarch64\bin;C:\Program Files\OpenSSL\bin;C:\tools\kotlinc\bin;C:\hostedtoolcache\windows\Java_Temurin-Hotspot_jdk\21.0.8-9.0\aarch64\bin;C:\Program Files (x86)\ImageMagick-7.1.2-Q16-HDRI;C:\Program Files\Microsoft SDKs\Azure\CLI2\wbin;C:\ProgramData\kind;C:\ProgramData\Chocolatey\bin;C:\Windows\system32;C:\Windows;C:\Windows\System32\Wbem;C:\Windows\System32\WindowsPowerShell\v1.0;C:\Windows\System32\OpenSSH;C:\Program Files\PowerShell\7;C:\Program Files\Microsoft\Web Platform Installer;C:\Program Files\Microsoft SQL Server\Client SDK\ODBC\170\Tools\Binn;C:\Program Files\Microsoft SQL Server\150\Tools\Binn;C:\Program Files\dotnet;C:\Program Files (x86)\Windows Kits\10\Windows Performance Toolkit;C:\Program Files\Microsoft SQL Server\130\DTS\Binn;C:\Program Files\Microsoft SQL Server\140\DTS\Binn;C:\Program Files\Microsoft SQL Server\150\DTS\Binn;C:\Program Files\Microsoft SQL Server\160\DTS\Binn;C:\Program Files\Microsoft SQL Server\170\DTS\Binn;C:\Strawberry\c\bin;C:\Strawberry\perl\site\bin;C:\Strawberry\perl\bin;C:\ProgramData\chocolatey\lib\pulumi\tools\Pulumi\bin;C:\Program Files\CMake\bin;C:\Tools\Ninja;C:\ProgramData\chocolatey\lib\maven\apache-maven-3.9.11\bin;C:\Program Files\LLVM\bin;C:\Program Files\nodejs;C:\Program Files\Git\cmd;C:\Program Files\Git\clangarm64\bin;C:\Program Files\Git\usr\bin;C:\Program Files\GitHub CLI;C:\tools\php;C:\Program Files (x86)\sbt\bin;C:\Program Files\Amazon\AWSCLIV2;C:\Program Files\Amazon\SessionManagerPlugin\bin;C:\Program Files\Amazon\AWSSAMCLI\bin;C:\Program Files\Microsoft SQL Server\130\Tools\Binn;C:\Users\runneradmin\.dotnet\tools;C:\Users\runneradmin\.cargo\bin;C:\Users\runneradmin\AppData\Local\Microsoft\WindowsApps
Extension DLL chain:
    dbghelp: image 10.0.26100.4654, API 10.0.6, 
        [path: C:\Program Files (x86)\Windows Kits\10\Debuggers\arm64\dbghelp.dll]
    exts: image 10.0.26100.1, API 1.0.0, 
        [path: C:\Program Files (x86)\Windows Kits\10\Debuggers\arm64\WINXP\exts.dll]
    uext: image 10.0.26100.1, API 1.0.0, 
        [path: C:\Program Files (x86)\Windows Kits\10\Debuggers\arm64\winext\uext.dll]
    ntsdexts: image 10.0.26100.1, API 1.0.0, 
        [path: C:\Program Files (x86)\Windows Kits\10\Debuggers\arm64\WINXP\ntsdexts.dll]
0:000> .nvlist
Loaded NatVis Files:
    <None Loaded>
0:000> bp `marker-types.rs:46`
*** WARNING: Unable to verify checksum for a.exe
0:000>  g
Breakpoint 0 hit
a!marker_types::main+0x90:
00007ff6`c5a712f8 97ffffdb bl          a!marker_types::zzz (00007ff6`c5a71264)
0:000>  dx nonnull
nonnull          : NonNull(0x7ff6c5a742f0: 0xc) [Type: core::ptr::non_null::NonNull<u32>]
    [<Raw View>]     [Type: core::ptr::non_null::NonNull<u32>]
    0xc [Type: unsigned int]
0:000>  dx manuallydrop
manuallydrop     : {...} [Type: core::mem::manually_drop::ManuallyDrop<i32>]
    [<Raw View>]     [Type: core::mem::manually_drop::ManuallyDrop<i32>]
    [+0x000] __0              : 12345 [Type: int]
0:000>  dx pin
pin              : Pin(0xe661aff5a8: "this") [Type: core::pin::Pin<ref_mut$<alloc::string::String> >]
    [<Raw View>]     [Type: core::pin::Pin<ref_mut$<alloc::string::String> >]
    [len]            : 0x4 [Type: unsigned __int64]
    [capacity]       : 0x4 [Type: unsigned __int64]
    [chars]          : "this"
0:000>  dx unique
unique           : Unique(0xe661aff5c0: (0x2a, 4321)) [Type: core::ptr::unique::Unique<tuple$<u64,i32> >]
    [<Raw View>]     [Type: core::ptr::unique::Unique<tuple$<u64,i32> >]
    [0]              : 0x2a [Type: unsigned __int64]
    [1]              : 4321 [Type: int]
0:000> qq
quit:
NatVis script unloaded from 'C:\Program Files (x86)\Windows Kits\10\Debuggers\arm64\Visualizers\atlmfc.natvis'
NatVis script unloaded from 'C:\Program Files (x86)\Windows Kits\10\Debuggers\arm64\Visualizers\ObjectiveC.natvis'
NatVis script unloaded from 'C:\Program Files (x86)\Windows Kits\10\Debuggers\arm64\Visualizers\concurrency.natvis'
NatVis script unloaded from 'C:\Program Files (x86)\Windows Kits\10\Debuggers\arm64\Visualizers\cpp_rest.natvis'
NatVis script unloaded from 'C:\Program Files (x86)\Windows Kits\10\Debuggers\arm64\Visualizers\stl.natvis'
NatVis script unloaded from 'C:\Program Files (x86)\Windows Kits\10\Debuggers\arm64\Visualizers\Windows.Data.Json.natvis'
NatVis script unloaded from 'C:\Program Files (x86)\Windows Kits\10\Debuggers\arm64\Visualizers\Windows.Devices.Geolocation.natvis'
NatVis script unloaded from 'C:\Program Files (x86)\Windows Kits\10\Debuggers\arm64\Visualizers\Windows.Devices.Sensors.natvis'
NatVis script unloaded from 'C:\Program Files (x86)\Windows Kits\10\Debuggers\arm64\Visualizers\Windows.Media.natvis'
NatVis script unloaded from 'C:\Program Files (x86)\Windows Kits\10\Debuggers\arm64\Visualizers\windows.natvis'
NatVis script unloaded from 'C:\Program Files (x86)\Windows Kits\10\Debuggers\arm64\Visualizers\winrt.natvis'
------------------------------------------
stderr: none

---- [debuginfo-cdb] tests\debuginfo\marker-types.rs stdout end ----

---

Some tests failed in compiletest suite=debuginfo mode=debuginfo host=aarch64-pc-windows-msvc target=aarch64-pc-windows-msvc
Bootstrap failed while executing `test --stage 2 --skip=compiler --skip=src`
Build completed unsuccessfully in 1:25:05
make: *** [Makefile:112: ci-msvc-py] Error 1
  local time: Wed Dec 17 23:29:22 CUT 2025
  network time: Wed, 17 Dec 2025 23:29:22 GMT
##[error]Process completed with exit code 2.
##[group]Run echo "disk usage:"
echo "disk usage:"

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bors commented Dec 17, 2025

💔 Test failed - checks-actions

@bors bors added S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. and removed S-waiting-on-bors Status: Waiting on bors to run and complete tests. Bors will change the label on completion. labels Dec 17, 2025
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