This particular version got moved into a `old_versions` subdirectory.
- python -m pip install --egg scons==2.4.1
- scons --version
# Install flex/bison
-- if not exist "%WINFLEXBISON_ARCHIVE%" appveyor DownloadFile "http://downloads.sourceforge.net/project/winflexbison/%WINFLEXBISON_ARCHIVE%"
+- if not exist "%WINFLEXBISON_ARCHIVE%" appveyor DownloadFile "https://downloads.sourceforge.net/project/winflexbison/old_versions/%WINFLEXBISON_ARCHIVE%"
- 7z x -y -owinflexbison\ "%WINFLEXBISON_ARCHIVE%" > nul
- set Path=%CD%\winflexbison;%Path%
- win_flex --version