Make clippy.toml an unstable feature

[oli-obk]

We could simply place it behind some sort of CLIPPY_UNSTABLE_CONFIG_TOML=1 flag that users can use but would need to be aware that we'd deprecate the support for it at some point and move to another file at which point the use of the env var would become an error (and the clippy.toml would get ignored)

discussion rust-lang/rfcs#2476 (comment)

[phansch]

Currently blocked due to pending decision at rust-lang/rfcs#2476 (comment)

[phansch]

Update: It was decided at the time that clippy.toml should be unstable in the RFC: rust-lang/rfcs#2476 (comment)

However, I do fear that it might be too late to make it unstable now (almost 2 years later)?

[flip1995]

I mean we could make it unstable in an edition (if also tools can use editions for such things). But only if we replace it with something stable, like a lints.toml file (I want to write a RFC for this soon).

Or we just introduce a warning for the clippy.toml file and provide tooling to convert it to the new configuration and support both for a few releases.

[tgross35]

Options for a config file are discussed more in depth on #6625 - since there isn't much discussion here, could this be closed as a duplicate?

[flip1995]

We'll probably won't turn this into an unstable feature now. We're way past this point.

[tgross35]

We'll probably won't turn this into an unstable feature now. We're way past this point.

I was kind of hoping it wouldn't go away 🙂 thanks for confirming