Here's Linus's answer inside the thread, which is quite positive: From: Linus Torvalds @ 2020-07-10 23:54 UTC (permalink / raw) To: Josh Triplett Cc: Chris

Here's Linus's answer inside the thread, which is quite positive: From: Linus Torvalds @ 2020-07-10 23:54 UTC (permalink / raw) To: Josh Triplett Cc: Christian Brauner, Nick Desaulniers, alex.gaynor, Greg KH, geofft, jbaublitz, Masahiro Yamada, Miguel Ojeda, Steven Rostedt, LKML, clang-built-linux, Kees Cook On Fri, Jul 10, 2020 at 3:59 PM Josh Triplett <josh@joshtriplett.org> wrote: > > As I recall, Greg's biggest condition for initial introduction of this > was to do the same kind of "turn this Kconfig option on and turn an > option under it off" trick that LTO uses, so that neither "make > allnoconfig" nor "make allyesconfig" would require Rust until we've had > plenty of time to experiment with it. No, please make it a "is rust available" automatic config option. The exact same way we already do the compiler versions and check for various availability of compiler flags at config time. See init/Kconfig for things like config LD_IS_LLD def_bool $(success,$(LD) -v | head -n 1 | grep -q LLD) and the rust support should be similar. Something like config RUST_IS_AVAILABLE def_bool $(success,$(RUST) ..sometest..) because I _don't_ want us to be in the situation where any new rust support isn't even build-tested by default. Quite the reverse. I'd want the first rust driver (or whatever) to be introduced in such a simple format that failures will be obvious and simple. The _worst_ situation to be in is that s (small) group of people start testing their very special situation, and do bad and crazy things because "nobody else cares, it's hidden". No, thank you.