[tmoertel]

The point is that “the deal” assumes that the Rust folks will keep their promises for the long haul. Which kernel maintainers, who have witnessed similar promises fall flat, are not willing to trust at face value.

What if, in years to come, the R4L effort peters out? Who will keep their promises then? And what will it cost those people to keep those broken promises?

The existing kernel maintainers mostly believe that the answers to the questions are “we will get stuck with the burden” and “it will be very expensive since we are not Rust programmers.”

[Szpadel]

Isn't it the same as with support for old hardware? Alpha arch, intel itanium, floppy drives?

Those are all in similar situation, where there is noone to maintain it as none of maintsiners have access to such hardware to event test of that is working correctly.

From time to time we see that such thing is discovered that is not working at all for long time and noone noticed and is dropped from kernel.

The same would happen to rust if noone would like to maintain it.

Rust for Linux is provided as experimental thing and if it won't gain traction it will be dropped in the same way curl dropped it.

[tmoertel]

The reason the maintainers can drop support for hardware nobody uses is that dropping support won't harm end users. The same cannot be expected of Rust in the kernel. The Rust For Linux folks, like most sensible programmers, intend to have impact. They are aiming to create abstractions and drivers that will deliver the benefits of Rust to users widely, eliminating classes memory errors, data races, and logic bugs. Rust will not be limited to largely disposable parts of Linux. Once it reaches even a small degree of inclusion it will be hard to remove without affecting end users substantially.