Adding comment to function causes "overflow evaluating the requirement"

[kjeremy]

$ rustc --version
rustc 1.32.0 (9fda7c2 2019-01-16)

$ rustup toolchain list
stable-x86_64-pc-windows-msvc (default)

Discovered when running cargo check on rust-analyzer. The command succeeds but adding a comment before (as in // this is a comment before https://github.com/rust-analyzer/rust-analyzer/blob/88702a758f031f33452e9acac621841552ec9f8a/crates/ra_lsp_server/src/main_loop/handlers.rs#L695

causes

$ cargo check
Checking ra_lsp_server v0.1.0 (C:\projects\test\rust-analyzer\crates\ra_lsp_server)
error[E0275]: overflow evaluating the requirement *const ra_hir::path::GenericArg: std::panic::RefUnwindSafe
--> crates\ra_lsp_server\src\main_loop.rs:491:10
|
491 | pool.execute(move || {
| ^^^^^^^
|
= help: consider adding a #![recursion_limit="128"] attribute to your crate
= note: required because it appears within the type core::nonzero::NonZero<*const ra_hir::path::GenericArg>
= note: required because it appears within the type std::ptr::Unique<ra_hir::path::GenericArg>
= note: required because it appears within the type alloc::raw_vec::RawVec<ra_hir::path::GenericArg>
= note: required because it appears within the type std::vec::Vec<ra_hir::path::GenericArg>
= note: required because it appears within the type ra_hir::path::GenericArgs
= note: required because it appears within the type alloc::sync::ArcInner<ra_hir::path::GenericArgs>
= note: required because it appears within the type *const alloc::sync::ArcInner<ra_hir::path::GenericArgs>
= note: required because it appears within the type core::nonzero::NonZero<*const alloc::sync::ArcInner<ra_hir::path::GenericArgs>>
= note: required because it appears within the type std::ptr::NonNull<alloc::sync::ArcInner<ra_hir::path::GenericArgs>>
= note: required because it appears within the type std::sync::Arc<ra_hir::path::GenericArgs>
= note: required because it appears within the type std::option::Option<std::sync::Arc<ra_hir::path::GenericArgs>>
= note: required because it appears within the type ra_hir::path::PathSegment
= note: required because it appears within the type *const ra_hir::path::PathSegment
= note: required because it appears within the type core::nonzero::NonZero<*const ra_hir::path::PathSegment>
= note: required because it appears within the type std::ptr::Unique<ra_hir::path::PathSegment>
= note: required because it appears within the type alloc::raw_vec::RawVec<ra_hir::path::PathSegment>
= note: required because it appears within the type std::vec::Vec<ra_hir::path::PathSegment>
= note: required because it appears within the type ra_hir::path::Path
= note: required because it appears within the type ra_hir::expr::Expr
= note: required because it appears within the type *const ra_hir::expr::Expr
= note: required because it appears within the type core::nonzero::NonZero<*const ra_hir::expr::Expr>
= note: required because it appears within the type std::ptr::Unique<ra_hir::expr::Expr>
= note: required because it appears within the type alloc::raw_vec::RawVec<ra_hir::expr::Expr>
= note: required because it appears within the type std::vec::Vec<ra_hir::expr::Expr>
= note: required because it appears within the type ra_arena::Arena<ra_hir::expr::ExprId, ra_hir::expr::Expr>
= note: required because it appears within the type ra_hir::expr::Body
= note: required because it appears within the type alloc::sync::ArcInner<ra_hir::expr::Body>
= note: required because it appears within the type *const alloc::sync::ArcInner<ra_hir::expr::Body>
= note: required because it appears within the type core::nonzero::NonZero<*const alloc::sync::ArcInner<ra_hir::expr::Body>>
= note: required because it appears within the type std::ptr::NonNull<alloc::sync::ArcInner<ra_hir::expr::Body>>
= note: required because it appears within the type std::sync::Arc<ra_hir::expr::Body>
= note: required because it appears within the type ra_hir::expr::scope::ExprScopes
= note: required because it appears within the type alloc::sync::ArcInner<ra_hir::expr::scope::ExprScopes>
= note: required because it appears within the type *const alloc::sync::ArcInner<ra_hir::expr::scope::ExprScopes>
= note: required because it appears within the type core::nonzero::NonZero<*const alloc::sync::ArcInner<ra_hir::expr::scope::ExprScopes>>
= note: required because it appears within the type std::ptr::NonNull<alloc::sync::ArcInner<ra_hir::expr::scope::ExprScopes>>
= note: required because it appears within the type std::sync::Arc<ra_hir::expr::scope::ExprScopes>
= note: required because of the requirements on the impl of std::panic::RefUnwindSafe for salsa::derived::DerivedStorage<ra_ide_api::db::RootDatabase, ra_hir::db::ExprScopesQuery, salsa::derived::AlwaysMemoizeValue>
= note: required because it appears within the type ra_hir::db::HirDatabaseGroupStorage__<ra_ide_api::db::RootDatabase>
= note: required because it appears within the type ra_ide_api::db::__SalsaDatabaseStorage
= note: required because of the requirements on the impl of std::panic::RefUnwindSafe for salsa::runtime::SharedState<ra_ide_api::db::RootDatabase>
= note: required because it appears within the type alloc::sync::ArcInner<salsa::runtime::SharedState<ra_ide_api::db::RootDatabase>>
= note: required because it appears within the type *const alloc::sync::ArcInner<salsa::runtime::SharedState<ra_ide_api::db::RootDatabase>>
= note: required because it appears within the type core::nonzero::NonZero<*const alloc::sync::ArcInner<salsa::runtime::SharedState<ra_ide_api::db::RootDatabase>>>
= note: required because it appears within the type std::ptr::NonNull<alloc::sync::ArcInner<salsa::runtime::SharedState<ra_ide_api::db::RootDatabase>>>
= note: required because it appears within the type std::sync::Arc<salsa::runtime::SharedState<ra_ide_api::db::RootDatabase>>
= note: required because it appears within the type salsa::runtime::RevisionGuard<ra_ide_api::db::RootDatabase>
= note: required because it appears within the type std::option::Option<salsa::runtime::RevisionGuard<ra_ide_api::db::RootDatabase>>
= note: required because it appears within the type salsa::runtime::Runtime<ra_ide_api::db::RootDatabase>
= note: required because it appears within the type ra_ide_api::db::RootDatabase
= note: required because of the requirements on the impl of ra_db::CheckCanceled for ra_ide_api::db::RootDatabase
= note: required because of the requirements on the impl of ra_db::SourceDatabase for ra_ide_api::db::RootDatabase
= note: required because of the requirements on the impl of salsa::plumbing::QueryGroup<ra_ide_api::db::RootDatabase> for ra_db::SourceDatabaseStorage
= note: required because it appears within the type ra_ide_api::db::__SalsaDatabaseStorage
= note: required because it appears within the type salsa::runtime::SharedState<ra_ide_api::db::RootDatabase>
= note: required because of the requirements on the impl of std::marker::Send for std::sync::Arc<salsa::runtime::SharedState<ra_ide_api::db::RootDatabase>>
= note: required because it appears within the type salsa::runtime::RevisionGuard<ra_ide_api::db::RootDatabase>

error: aborting due to previous error

For more information about this error, try rustc --explain E0275.
error: Could not compile ra_lsp_server.

[jonas-schievink]

Can reproduce. Starts working again after running cargo clean, so marking as incr. comp. bug

[jonas-schievink]

Ah, looks like this is already fixed on nightly though. Can someone confirm?

[kjeremy]

Still happening on 1.33.0

[jonas-schievink]

@kjeremy can you try on nightly/beta please?

[kjeremy]

This particular error doesn't seem to happen on nightly anymore.

[Dylan-DPC]

@kjeremy can you confirm if this still occurs on the latest stable & nightly? or is this fixed already? [sorry for the 4 year later ping :P ]

[apiraino]

Closing as this incr-comp issue is old and we never managed to obtain an MCVE or a way to reproduce. the issue is supposedly fixed