appveyor vcpkg seemingly corrupts itself #19440
Description
This is the second time this week, see https://ci.appveyor.com/project/DrahtBot/bitcoin/history
Failure looks like:
msbuild /p:TrackFileAccess=false build_msvc\bitcoin.sln /m /v:q /nologo
C:\projects\bitcoin\src\util\url.cpp(7,10): fatal error C1083: Cannot open include file: 'event2/http.h': No such file or directory [C:\projects\bitcoin\build_msvc\libbitcoin_util\libbitcoin_util.vcxproj]
C:\projects\bitcoin\src\script\standard.h(12,10): fatal error C1083: Cannot open include file: 'boost/variant.hpp': No such file or directory [C:\projects\bitcoin\build_msvc\libbitcoin_common\libbitcoin_common.vcxproj]