[Copilot]

Fixes Issue

main PR

Description

CMake 4.2.0 changed the default PDB location for OBJECT libraries from ${CMAKE_CURRENT_BINARY_DIR}/$<CONFIG>/ to CMakeFiles/<target>.dir/, causing install step failures when the build system couldn't find bootstrapper.pdb.

Changes:

• Set COMPILE_PDB_OUTPUT_DIRECTORY to "${CMAKE_CURRENT_BINARY_DIR}/$<CONFIG>" for bootstrapper OBJECT library
• Unified install path to consistently use $<CONFIG> for all MSVC generators (removed Visual Studio vs. Ninja conditional)

Follows existing pattern from eventpipe-shared-objects OBJECT library.

Customer Impact

Builds fail completely with CMake 4.2.0-rc4+ on Windows. Developers cannot build the repo with latest CMake versions, blocking contribution and testing.

Regression

No. This is a new failure introduced by CMake 4.2.0's behavior change, not a regression in runtime code.

Testing

Build configuration change validated against:

• Existing pattern used successfully in eventpipe-shared-objects OBJECT library
• CMake documentation for COMPILE_PDB_OUTPUT_DIRECTORY property
• Code review and security scan passed

Risk

Low. Minimal change affecting only Windows MSVC builds of OBJECT libraries in nativeaot bootstrapper. No code logic changes, only CMake build configuration to adapt to CMake 4.2.0's new intermediate directory strategy.

Package authoring no longer needed in .NET 9

IMPORTANT: Starting with .NET 9, you no longer need to edit a NuGet package's csproj to enable building and bump the version.
Keep in mind that we still need package authoring in .NET 8 and older versions.

Original prompt

---

This section details on the original issue you should resolve

<issue_title>Repo doesn't build with latest CMake</issue_title>
<issue_description>### Description

As of today, current version of CMake is: Release Candidate (4.2.0-rc4) which causes build errors.

3.31.9 - works fine.

Reproduction Steps

• fresh VM
• install git, latest cmake, VS etc.
• build -rc Release -s clr+libs

Expected behavior

builds fine

Actual behavior

Error

...
CMake Error at nativeaot/Bootstrap/base/cmake_install.cmake:45 (file):
  file INSTALL cannot find
  "C:/src/runtime/artifacts/obj/coreclr/windows.x64.Release/nativeaot/Bootstrap/base/bootstrapper.pdb":
  File exists.
Call Stack (most recent call first):
  nativeaot/Bootstrap/cmake_install.cmake:42 (include)
  nativeaot/cmake_install.cmake:42 (include)
  cmake_install.cmake:97 (include)


FAILED: CMakeFiles/install.util
C:\Windows\system32\cmd.exe /C "cd /D C:\src\runtime\artifacts\obj\coreclr\windows.x64.Release && "C:\Program Files\CMake\bin\cmake.exe" -P cmake_install.cmake"
ninja: build stopped: subcommand failed.
BUILD: Error: native component build failed. Refer to the build log files for details.
    "C:\src\runtime\artifacts\log\Release\CoreCLR_windows__x64__Release__x64.log"
    "C:\src\runtime\artifacts\log\Release\CoreCLR_windows__x64__Release__x64.wrn"
    "C:\src\runtime\artifacts\log\Release\CoreCLR_windows__x64__Release__x64.err"
C:\src\runtime\src\coreclr\runtime.proj(115,5): error MSB3073: The command ""C:\src\runtime\src\coreclr\build-runtime.cmd" -x64 -release -os windows -pgodatapath "C:\Users\kwicher\.nuget\packages\optimization.windows_nt-x64.pgo.coreclr\1.0.0-prerelease.25502.1" -targetrid win-x64 -cmakeargs "-DCLR_DOTNET_RID=win-x64" -cmakeargs "-DCLR_DOTNET_HOST_PATH=C:\src\runtime\.dotnet\dotnet.exe" -cmakeargs "-DCDAC_BUILD_TOOL_BINARY_PATH=C:\src\runtime\artifacts\bin\coreclr\windows.x64.Release\cdac-build-tool\cdac-build-tool.dll" -cmakeargs "-DCLR_CMAKE_RUNTIME_CORECLR=1" -cmakeargs "-DCMAKE_PRODUCT_VERSION=10.0.0" -cmakeargs "-DCMAKE_CONTINUOUS_INTEGRATION_BUILD=False" -cmakeargs "-DCMAKE_NET_CORE_APP_CURRENT_VERSION=10.0" -cmakeargs "-DCMAKE_BUILD_LIBRARIES_CONFIGURATION=Debug" -cmakeargs "-DCMAKE_BUILD_RUNTIME_CONFIGURATION=Release"" exited with code 1.

Build FAILED.

C:\src\runtime\src\coreclr\runtime.proj(115,5): error MSB3073: The command ""C:\src\runtime\src\coreclr\build-runtime.cmd" -x64 -release -os windows -pgodatapath "C:\Users\kwicher\.nuget\packages\optimization.windows_nt-x64.pgo.coreclr\1.0.0-prerelease.25502.1" -targetrid win-x64 -cmakeargs "-DCLR_DOTNET_RID=win-x64" -cmakeargs "-DCLR_DOTNET_HOST_PATH=C:\src\runtime\.dotnet\dotnet.exe" -cmakeargs "-DCDAC_BUILD_TOOL_BINARY_PATH=C:\src\runtime\artifacts\bin\coreclr\windows.x64.Release\cdac-build-tool\cdac-build-tool.dll" -cmakeargs "-DCLR_CMAKE_RUNTIME_CORECLR=1" -cmakeargs "-DCMAKE_PRODUCT_VERSION=10.0.0" -cmakeargs "-DCMAKE_CONTINUOUS_INTEGRATION_BUILD=False" -cmakeargs "-DCMAKE_NET_CORE_APP_CURRENT_VERSION=10.0" -cmakeargs "-DCMAKE_BUILD_LIBRARIES_CONFIGURATION=Debug" -cmakeargs "-DCMAKE_BUILD_RUNTIME_CONFIGURATION=Release"" exited with code 1.
    0 Warning(s)
    1 Error(s)

Time Elapsed 00:07:08.28
Build failed with exit code 1. Check errors above.
Some builds failed:
        Configuration: Debug, Architecture: x64(this is just end of the log)

Regression?

not on .NET side

Known Workarounds

install old cmake

Configuration

No response

Other information

No response</issue_description>

Comments on the Issue (you are @copilot in this section)

@ericstj I'm hitting the same @agocke any idea how to fix this? I don't see any earlier failure, just that the build didn't produce a PDB in the location that it's trying to install. ``` CMake Error at nativeaot/Bootstrap/base/cmake_install.cmake:45 (file): file INSTALL cannot find "C:/src/dotnet/runtime/artifacts/obj/coreclr/windows.x64.Release/nativeaot/Bootstrap/base/bootstrapper.pdb": File exists. Call Stack (most recent call first): nativeaot/Bootstrap/cmake_install.cmake:42 (include) nativeaot/cmake_install.cmake:42 (include) cmake_install.cmake:97 (include) ```

I do see it in a sub-directory:

C:\src\dotnet\runtime\artifacts>dir /s /b bootstrapper.pdb
C:\src\dotnet\runtime\artifacts\obj\coreclr\windows.x64.Release\nativeaot\Bootstrap\base\CMakeFiles\bootstrapper.dir\bootstrapper.pdb
```</body></comment_new>
<comment_new><author>@agocke</author><body>
I'm not a cmake expert, but we can try copilot.</body></comment_new>
</comments>

• Fixes Repo doesn't build with latest CMake #121788

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[ericstj]

I pulled this fix locally and it did resolve it for me. I'm building on Windows with Dev18.

[agocke]

@ericstj Thanks for the validation.

This change LGTM, but as I said I'm not a CMake expert.

[Copilot]

Pull request overview

This PR fixes a build failure with CMake 4.2.0+ by updating the nativeaot bootstrapper's PDB file handling to accommodate CMake's changed default PDB location for OBJECT libraries.

Key changes:

• Set COMPILE_PDB_OUTPUT_DIRECTORY to explicitly place PDB files in the expected $<CONFIG> subdirectory
• Unified the install path to consistently use $<CONFIG> for all MSVC generators, removing the Visual Studio vs. Ninja conditional

[jkoritzinsky]

As the resident CMake expert (or closest we have to it) LGTM

[jkoritzinsky]

/ba-g Helix infra issue