Remove suggestion from importing unstable items on stable channel

[chenyukang]

Fixes #149402

[rustbot]

r? @fee1-dead

rustbot has assigned @fee1-dead.
They will have a look at your PR within the next two weeks and either review your PR or reassign to another reviewer.

Use r? to explicitly pick a reviewer

[fee1-dead]

r=me after addressing nit

View changes since this review

[fee1-dead]

Is it possible to use revisions here to avoid duplicating the same file?

[chenyukang]

thanks, fixed in https://github.com/rust-lang/rust/compare/5b003456246ad18d3141eb748d750f152f51194f..34c80e46389304d906fcb50efe4cf32a0270fab7

[chenyukang]

@bors r=fee1-dead

[bors]

📌 Commit 34c80e4 has been approved by fee1-dead

It is now in the queue for this repository.

[bors]

⌛ Testing commit 34c80e4 with merge 2699798...

[bors]

⌛ Testing commit 34c80e4 with merge 8787ed6...

[rust-log-analyzer]

The job x86_64-gnu-stable failed! Check out the build log: (web) (plain enhanced) (plain)

Click to see the possible cause of the failure (guessed by this bot)

Saved the actual stderr to `/checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/resolve/suggest-unresolve-149402.stable/suggest-unresolve-149402.stable.stderr`
diff of stderr:

3    |
4 LL |     x.push(Complete::Item { name: "hello" });
5    |            ^^^^^^^^ use of undeclared type `Complete`
+    |
+ help: there is an enum variant `std::ops::CoroutineState::Complete`; try using the variant's enum
+    |
+ LL -     x.push(Complete::Item { name: "hello" });
+ LL +     x.push(std::ops::CoroutineState::Item { name: "hello" });
+    |
6 
7 error: aborting due to 1 previous error
8 


The actual stderr differed from the expected stderr
To update references, rerun the tests and pass the `--bless` flag
To only update this specific test, also pass `--test-args resolve/suggest-unresolve-149402.rs`

error in revision `stable`: 1 errors occurred comparing output.
status: exit status: 1
command: env -u RUSTC_LOG_COLOR RUSTC_ICE="0" RUST_BACKTRACE="short" "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2/bin/rustc" "/checkout/tests/ui/resolve/suggest-unresolve-149402.rs" "-Zthreads=1" "-Zsimulate-remapped-rust-src-base=/rustc/FAKE_PREFIX" "-Ztranslate-remapped-path-to-local-path=no" "-Z" "ignore-directory-in-diagnostics-source-blocks=/cargo" "-Z" "ignore-directory-in-diagnostics-source-blocks=/checkout/vendor" "--sysroot" "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2" "--target=x86_64-unknown-linux-gnu" "--cfg" "stable" "--check-cfg" "cfg(test,FALSE,stable,nightly)" "--error-format" "json" "--json" "future-incompat" "-Ccodegen-units=1" "-Zui-testing" "-Zdeduplicate-diagnostics=no" "-Zwrite-long-types-to-disk=no" "-Cstrip=debuginfo" "--emit" "metadata" "-C" "prefer-dynamic" "--out-dir" "/checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/resolve/suggest-unresolve-149402.stable" "-A" "unused" "-W" "unused_attributes" "-A" "internal_features" "-A" "unused_parens" "-A" "unused_braces" "-Crpath" "-Cdebuginfo=0" "-Lnative=/checkout/obj/build/x86_64-unknown-linux-gnu/native/rust-test-helpers"
stdout: none
--- stderr -------------------------------
error[E0433]: failed to resolve: use of undeclared type `Complete`
##[error]  --> /checkout/tests/ui/resolve/suggest-unresolve-149402.rs:7:12
   |
LL |     x.push(Complete::Item { name: "hello" });
   |            ^^^^^^^^ use of undeclared type `Complete`
   |
help: there is an enum variant `std::ops::CoroutineState::Complete`; try using the variant's enum
   |
LL -     x.push(Complete::Item { name: "hello" });
LL +     x.push(std::ops::CoroutineState::Item { name: "hello" });
   |

error: aborting due to 1 previous error

For more information about this error, try `rustc --explain E0433`.

[bors]

💔 Test failed - checks-actions

[chenyukang]

@jieyouxu
do you know how to add test case only for stable channel?

I build a stage2 on local machine, and found out the is_nightly_build() returns true, I think it's the same in CI testing.

https://github.com/chenyukang/rust/blob/34c80e46389304d906fcb50efe4cf32a0270fab7/compiler/rustc_resolve/src/diagnostics.rs#L1612

From the code, seems we will set CFG_DISABLE_UNSTABLE_FEATURES for stable channel.
https://github.com/chenyukang/rust/blob/34c80e46389304d906fcb50efe4cf32a0270fab7/compiler/rustc_feature/src/lib.rs#L84

[jieyouxu]

Ok, it looks like RUSTC_BOOTSTRAP overriding CFG_DISABLE_UNSTABLE_FEATURES is intentional (at least, that's what the original logic was also doing), as otherwise, you can't even bootstrap.

One option you may have is to write this as a run-make test, with two stderr tracked: a stable rustc, and an unstable rustc. Gate the run-make itself using //@ only-nightly, but have the nightly rustc "pretend" to be a stable rustc with RUSTC_BOOTSTRAP=-1. Have a look at

rust/tests/run-make/print-request-help-stable-unstable/rmake.rs

Line 8 in dfe1b8c

.env("RUSTC_BOOTSTRAP", "-1")

for an example. That should still allow you to compare the diffs generated by the same rustc as if it reached stable.