message: Try w/o deltree
diff: @@ -32,13 +32,12 @@ jobs:
  (new-object System.Net.WebClient).DownloadFile('https://github.com/microsoft/vcpkg/files/4978792/vcpkg_fixup_pkgconfig.cmake.txt','c:\vcpkg\scripts\cmake\vcpkg_fixup_pkgconfig.cmake')
  (new-object System.Net.WebClient).DownloadFile('https://github.com/microsoft/vcpkg/files/4978796/vcpkg_acquire_msys.cmake.txt','c:\vcpkg\scripts\cmake\vcpkg_acquire_msys.cmake')
  shell: powershell
  +# deltree "c:\vcpkg\downloads\tools\msys2"
  - name: Install dependencies
  run: |
  - deltree "c:\vcpkg\downloads\tools\msys2"
  vcpkg update
  vcpkg upgrade --no-dry-run
  vcpkg install boost-graph boost-serialization boost-date-time boost-system boost-filesystem boost-units boost-thread boost-program-options eigen3 mpfr mpir cgal --triplet x64-windows
  - vcpkg list
  python -m pip install --user -r .github/build-requirements.txt
  python -m pip install --user twine
  python -m pip list
  