build: AppVeyor build uses Libevent that built without support for evthread_use_windows_threads() #17586

With this patch to master:

https://ci.appveyor.com/project/hebasto/bitcoin/builds/29096172

Ref: EVTHREAD_USE_WINDOWS_THREADS_IMPLEMENTED

Seems that, while an unlikely build configuration, it's still possible to build libevent without thread support (we obviously don't support this):

cmake EVENT_CMAKE_OPTIONS="-DEVENT__DISABLE_THREAD_SUPPORT=ON"

Though it's curious that the AppVeyor error is a link-time error, not a compile-time error. So apparently in the header it does still define the function signature for evthread_use_windows_threads.

Though it's curious that the AppVeyor error is a link-time error, not a compile-time error.

The latest builds have compile-time errors.

I've confirmed I get the same compiler error after installing libevent using the latest vcpkg port. The error is caused by the line below in the port file. Commenting that line out and reinstalling the libevent package allows the build to succeed.

thread  EVENT__DISABLE_THREAD_SUPPORT

One way to fix the build issue is to create a custom libevent port and then perform the vcpkg install using:

vcpkg install --triplet x64-windows-static --overlay-ports=..\vcpkg-custom-ports\ports berkeleydb boost-filesystem boost-multi-index boost-signals2 boost-test boost-thread libevent rapidcheck zeromq double-conversion

Any ports in the ..\vcpkg-custom-ports\ports take precedence.

@sipsorcery I think you need to request the "thread" feature explicitly now, somehow

I'm not a msvc-guru, so it is curious if there is a way to specify the package version in vcpkg install ...?

Wumpus has just enlightened me to vcpkg's Feature Packages. Testing that now. @hebasto no vcpkg does not allow specifying of a specific version. The Overlay Ports is a defacto way to do it but it does require additional steps.

Hi guys, thanks for reporting this issue! I will handle it tomorrow.

Fixed in #17592.