Override which spawn strategy should be used to execute spawn actions that have descriptions matching a certain regex_filter. See --per_file_copt for details onregex_filter matching. The last regex_filter that matches the description is used. This option overrides other flags for specifying strategy. Example: --strategy_regexp=//foo.*\.cc,-//foo/bar=local means to run actions using local strategy if their descriptions match //foo.*.cc but not //foo/bar. Example: --strategy_regexp='Compiling.*/bar=local -- strategy_regexp=Compiling=sandboxed will run 'Compiling //foo/bar/baz' with the 'local' strategy, but reversing the order would run it with 'sandboxed'.