A coworker asked about this option. It looks like clang renamed -fsanitize-blacklist to -fsanitize-ignorelist at some point:
https://clang.llvm.org/docs/UsersManual.html#cmdoption-fsanitize-ignorelist

sccache already supports the old name, so this should be a simple fix.