-Z time-passes=val -- measure time of each rustc pass (default: no)
-Z tls-model=val -- choose the TLS model to use (`rustc --print tls-models` for details)
-Z trace-macros=val -- for every macro invocation, print its name and arguments (default: no)
+ -Z track-diagnostics=val -- tracks where in rustc a diagnostic was emitted
-Z translate-additional-ftl=val -- additional fluent translation to preferentially use (for testing translation)
-Z translate-directionality-markers=val -- emit directionality isolation markers in translated diagnostics
-Z translate-lang=val -- language identifier for diagnostic output