[Bug]: Windows build does not work with latest version of Visual Studio #1534

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1. marcnause commented on May 24, 2026

   

   marcnause

   on May 24, 2026

   Author

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   Removing the following line from permission_handler_windows/windows/CMakeLists.txt made it work for me:

   target_compile_options(${PLUGIN_NAME} PRIVATE /await)

   👍React with 👍2Reacted by 挥手的骑士 and Binoy
2. kjxbyz commented on Jun 10, 2026

   

   kjxbyz

   on Jun 10, 2026

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   Same issue.

   C:\Program Files\Microsoft Visual Studio\18\Enterprise\VC\Tools\MSVC\14.51.36231\include\experimental\coroutine(37,1): error C2338: static assertion failed: 'error STL1011: The /await compiler option, <experimental/coroutine>, <experimental/generator>, and <experimental/resumable> are deprecated by Microsoft and will be REMOVED SOON. They are superseded by the C++20 <coroutine> and C++23 <generator> headers. You can define _SILENCE_EXPERIMENTAL_COROUTINE_DEPRECATION_WARNINGS to suppress this error for now.' [D:\a\picguard\picguard\build\windows\x64\plugins\permission_handler_windows\permission_handler_windows_plugin.vcxproj]
   D:\a\picguard\picguard\build\windows\x64\_deps\sentry-native-src\external\breakpad\src\common\md5.cc(74,23): warning C4267: '+=': conversion from 'size_t' to 'google_breakpad::u32', possible loss of data [D:\a\picguard\picguard\build\windows\x64\_deps\sentry-native-build\external\breakpad_client.vcxproj]
   
3. kjxbyz commented on Jun 23, 2026

   

   kjxbyz

   on Jun 23, 2026

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   Workaround until the plugin migrates to C++20 , define the silence macro before the plugins are added in the app's windows/CMakeLists.txt:

   add_compile_definitions(_SILENCE_EXPERIMENTAL_COROUTINE_DEPRECATION_WARNINGS)
4. adil192

   added a commit that references this issue on Jul 1, 2026

   perf: remove `permission_handler` from linux/windows builds

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   6c6d94d
5. grunch

   added a commit that references this issue on Sep 18, 2026

   fix(windows): silence the experimental-coroutine error from permissio…

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   f834522
6. agentx-icu commented on Sep 26, 2026

   

   agentx-icu

   on Sep 26, 2026

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   Another data point, plus the precise mechanism, since the thread has two competing workarounds and only one of them addresses the cause.

   Confirming this on Windows ARM64 and on GitHub-hosted CI. A Flutter app of ours builds Windows x64 and ARM64 in CI. The ARM64 job runs on windows-11-arm, whose image moved to Visual Studio 18 (cl.exe from .../Microsoft Visual Studio/18/Enterprise/VC/Tools/MSVC/14.51.36231/bin/HostARM64/ARM64, Windows SDK 10.0.26100.0), and every build now fails with:

   C:\Program Files\Microsoft Visual Studio\18\Enterprise\VC\Tools\MSVC\14.51.36231\include\experimental\coroutine(37,1): error C2338: static assertion failed: 'error STL1011: The /await compiler option, <experimental/coroutine>, <experimental/generator>, and <experimental/resumable> are deprecated by Microsoft and will be REMOVED SOON. They are superseded by the C++20 <coroutine> and C++23 <generator> headers. You can define _SILENCE_EXPERIMENTAL_COROUTINE_DEPRECATION_WARNINGS to suppress this error for now.' [...\build\windows\x64\plugins\permission_handler_windows\permission_handler_windows_plugin.vcxproj]
   

   Our x64 job still passes only because it is pinned to windows-2022 (MSVC 14.44); the same image family with VS 18 fails on x64 too, as the logs earlier in this thread show. Versions: permission_handler 11.4.0 -> permission_handler_windows 0.2.1, but 0.2.2 and main are identical in the part that matters.

   Minimal repro: any Flutter Windows app that depends on permission_handler, built with VS 18 / MSVC 14.51 (flutter build windows). No plugin API call is needed — it is a compile error in the plugin target.

   Why it happens — the cause is /await, not the C++ standard. C++/WinRT picks its coroutine header on one macro (strings/base_includes.h, unchanged in the pinned Microsoft.Windows.CppWinRT 2.0.210806.1 this plugin generates its headers with):

   #ifdef __cpp_lib_coroutine
   #include <coroutine>
   ...
   #else
   #include <experimental/coroutine>

   MSVC's STL defines __cpp_lib_coroutine only #ifdef __cpp_impl_coroutine (stl/inc/yvals_core.h), and /await selects the pre-standardization coroutine mode instead of the standard one — so permission_handler_windows lands in <experimental/coroutine> even though it already compiles as cxx_std_20, and MSVC 14.51 made that header a hard error.

   We can show both halves of that from one build. The same app also uses audioplayers_windows, which hit the identical STL1011 for a different reason — it requests no standard of its own, so it inherited the Flutter template's cxx_std_17. Raising just that target to cxx_std_20 made its errors disappear, while permission_handler_windows_plugin kept failing at cxx_std_20. The one difference between the two targets is /await.

   That is also why add_compile_definitions(_SILENCE_EXPERIMENTAL_COROUTINE_DEPRECATION_WARNINGS) in the app's windows/CMakeLists.txt "works": it silences the assertion while still compiling against a header Microsoft says is being removed. It buys time, it is not a fix. For the record, what we currently carry in our app is the same stopgap, scoped to this one target so the rest of the app keeps its standard:

   if(TARGET permission_handler_windows_plugin)
     target_compile_features(permission_handler_windows_plugin PRIVATE cxx_std_20)
     target_compile_definitions(permission_handler_windows_plugin
       PRIVATE _SILENCE_EXPERIMENTAL_COROUTINE_DEPRECATION_WARNINGS)
   endif()

   Suggestion: drop /await from the plugin's own windows/CMakeLists.txt — which is exactly what #1569 does (and what #1535 did before it was closed for an unrelated CI check). The target is already cxx_std_20, so co_await in IsBluetoothServiceEnabled compiles through standard <coroutine>; the pinned CppWinRT 2.0.210806.1 already has the __cpp_lib_coroutine branch, so no nuget bump is needed. It is also the only future-proof option: current C++/WinRT replaced that fallback with a hard #error "C++/WinRT no longer supports pre-standardization coroutines. ... If you do not [use co_await], remove /await from the compiler flags.", so /await will stop working regardless of the STL macro.

   For comparison, audioplayers fixed the C++17 variant of this in the plugin package itself (bluefireteam/audioplayers#2011, released in audioplayers_windows 4.4.1) rather than asking apps to patch their CMake — which is the shape of fix that lets apps just upgrade.
7. alfrededison

   added 3 commits that reference this issue on Oct 8, 2026

   Depend only on the Android permission_handler implementation

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   1161716

   Depend only on the Android permission_handler implementation

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   d88af57

   Depend only on the Android permission_handler implementation

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   8f362d3