Survey pinpoints Rust compiler pain points

## Although many users are satisfied with Rust build performance, a significant fraction of users report that slow builds and rebuilds in several common workflows are a ‘big problem’ for them. Overall, developers using Rust are satisfied with Rust compilation performance, but slow builds and rebuilds in several common workflows limit the productivity for a significant fraction of Rust users, according to the Rust Compiler Performance Survey, which was conducted the past two months by the Rust compiler performance working group. ... “While it is great to see some developers being happy with the state we have today, it is clear that many people are not so lucky, and Rust’s build performance limits their productivity,” said Jakub Beranek on behalf of the working group. “Around 45% of respondents who answered that they are no longer using Rust said that at least one of the reasons why they stopped were long compile times.” The survey found that the Rust build experience “differs wildly across users and workflows” and is not as clear-cut as “Rust builds are slow,” Beranek said. ... Challenges developers face with Rust build performance were not always as simple as slow compiler performance, said Beranek. ... Other findings of the Rust Compiler Performance Survey: - Waiting too long for an incremental rebuild after making a small source code change was by far the most common complaint in open answers received. - The incremental build of a single Rust compilation crate was too slow. - Several users mentioned that they would like to see Rust perform hot patching. - When Rust developers experience slow builds, it can be challenging to identify where exactly the compilation process is spending time, and what the bottleneck could be.