Ensure your HTTP_PROXY and HTTPS_PROXY environment variables are set correctly for CMake.
# Example in ExternalProject_Add ExternalProject_Add(my_dependency URL "https://example.com" URL_HASH SHA256=NEW_ACTUAL_HASH_HERE ) Use code with caution. cmake file download hash mismatch
If your internet connection drops or a firewall blocks the download, CMake might save a partial or empty file (often resulting in the specific da39a3ee... empty-file hash). cmake file download hash mismatch