Error map

Cannot start a runtime from within a runtime (Tokio) Rust: thread 'main' panicked: Cannot start a runtime from within a runtime — a function like `block_on` tried to block a thread that drives async tasks

Rust · layer 4, Application & API

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4 · Application & API 6 · Platform & cloud
Cannot start a runtime from within a runtime (Tokio) — Rust: thread 'main' panicked: Cannot start a runtime from within a runtime — a function like `block_on` tried to block a thread that drives async tasks (Rust)Cannot star…there is no reactor running, must be called from the context of a Tokio 1.x runtime — Rust: thread 'main' panicked: there is no reactor running, must be called from the context of a Tokio 1.x runtime (Rust)there is no reactor…Blocking waiting for file lock on package cache / build directory — Cargo: Blocking waiting for file lock on package cache / on build directory (Rust)Blocking waiting fo…E0728: await is only allowed inside async functions and blocks — Rust: error[E0728]: `await` is only allowed inside `async` functions and blocks (Rust)E0728: await is onl…E0752: main function is not allowed to be async — Rust: error[E0752]: `main` function is not allowed to be `async` (Rust)E0752: main functio…E0521: borrowed data escapes outside of function — Rust: error[E0521]: borrowed data escapes outside of function — `data` escapes the function body here (tokio::spawn requires 'static) (Rust)E0521: borrowed dat…cargo: failed to select a version for the requirement — Cargo: error: failed to select a version for the requirement `serde = "^2.0"` — candidate versions found which didn't match: 1.0.197 (Rust)cargo: failed to se…cargo: failed to get from registry (spurious network error) — Cargo: warning: spurious network error (2 tries remaining): [35] SSL connect error / error: failed to download from `https://index.crates.io/...` (Rust)cargo: failed to ge…E0499: cannot borrow as mutable more than once at a time — Rust: error[E0499]: cannot borrow `v` as mutable more than once at a time (Rust)E0499: cannot borro…E0505: cannot move out of value because it is borrowed — Rust: error[E0505]: cannot move out of `s` because it is borrowed (Rust)E0505: cannot move …E0507: cannot move out of a shared reference / index — Rust: error[E0507]: cannot move out of `self.name` which is behind a shared reference (Rust)E0507: cannot move …E0433: failed to resolve: use of undeclared type or module — Rust: error[E0433]: failed to resolve: use of undeclared type `HashMap` (Rust)E0433: failed to re…E0502 — Rust: error[E0502]: cannot borrow `x` as mutable because it is also borrowed as immutable (Rust)E0502E0106: missing lifetime specifier — Rust: error[E0106]: missing lifetime specifier — this function's return type contains a borrowed value, but the signature does not say which one of `x`'s 2 lifetimes it is borrowed from (Rust)E0106: missing life…E0597: borrowed value does not live long enough — Rust: error[E0597]: `x` does not live long enough — borrowed value does not live long enough (Rust)E0597: borrowed val…held broken packages — Unmet dependencies / E: Unable to correct problems, you have held broken packages (Linux)held broken packagesE0373: closure may outlive the current function — Rust: error[E0373]: closure may outlive the current function, but it borrows `v`, which is owned by the current function (Rust)E0373: closure may …E0277: the trait bound is not satisfied — Rust: error[E0277]: the trait bound `Foo: Display` is not satisfied / `Rc<RefCell<T>>` cannot be sent between threads safely (Rust)E0277: the trait bo…ssh port 22 Connection refused — ssh: connect to host x port 22: Connection refused (Linux)ssh port 22 Connect…ssh port 22 Connection timed out — ssh: connect to host x port 22: Connection timed out (Linux)ssh port 22 Connect…Temporary failure in name resolution — ping: google.com: Temporary failure in name resolution (Linux)Temporary failure i…

Directly related (7)

there is no reactor running, must be called from the context of a Tokio 1.x runtimeRust

Rust: thread 'main' panicked: there is no reactor running, must be called from the context of a Tokio 1.x runtime

A Tokio API (timer, TCP, `tokio::spawn`) was used outside a running Tokio runtime.

Blocking waiting for file lock on package cache / build directoryRust

Cargo: Blocking waiting for file lock on package cache / on build directory

Another cargo process (or rust-analyzer/IDE) holds the lock, so this command waits.

E0728: await is only allowed inside async functions and blocksRust

Rust: error[E0728]: `await` is only allowed inside `async` functions and blocks

You used `.await` in a normal (sync) function or closure.

E0752: main function is not allowed to be asyncRust

Rust: error[E0752]: `main` function is not allowed to be `async`

`async fn main()` needs a runtime attribute (Tokio/async-std), the std `main` can't be async.

E0521: borrowed data escapes outside of functionRust

Rust: error[E0521]: borrowed data escapes outside of function — `data` escapes the function body here (tokio::spawn requires 'static)

A reference was passed to something requiring `'static` (spawn tasks/threads) but it borrows local data.

cargo: failed to select a version for the requirementRust

Cargo: error: failed to select a version for the requirement `serde = "^2.0"` — candidate versions found which didn't match: 1.0.197

Cargo can't find a version of a dependency satisfying the constraints you (or other crates) set.

cargo: failed to get from registry (spurious network error)Rust

Cargo: warning: spurious network error (2 tries remaining): [35] SSL connect error / error: failed to download from `https://index.crates.io/...`

Cargo couldn't reach crates.io (network, proxy, TLS or DNS issues).

Two steps away (13)

E0499: cannot borrow as mutable more than once at a timeRust

Rust: error[E0499]: cannot borrow `v` as mutable more than once at a time

Two mutable references to the same value were alive at once, which Rust forbids.

E0505: cannot move out of value because it is borrowedRust

Rust: error[E0505]: cannot move out of `s` because it is borrowed

You moved a value while a reference to it was still in use.

E0507: cannot move out of a shared reference / indexRust

Rust: error[E0507]: cannot move out of `self.name` which is behind a shared reference

You tried to take ownership of a value through a reference (or from a Vec/Option behind `&`).

E0433: failed to resolve: use of undeclared type or moduleRust

Rust: error[E0433]: failed to resolve: use of undeclared type `HashMap`

A path starts with a name that isn't in scope (a type or module you didn't import).

E0502Rust

Rust: error[E0502]: cannot borrow `x` as mutable because it is also borrowed as immutable

You tried to mutate a value while an immutable reference to it is still in use.

E0106: missing lifetime specifierRust

Rust: error[E0106]: missing lifetime specifier — this function's return type contains a borrowed value, but the signature does not say which one of `x`'s 2 lifetimes it is borrowed from

The compiler can't infer which input reference the returned/stored reference is tied to.

E0597: borrowed value does not live long enoughRust

Rust: error[E0597]: `x` does not live long enough — borrowed value does not live long enough

A reference outlives the value it points to (the value is dropped first).

held broken packagesLinux

Unmet dependencies / E: Unable to correct problems, you have held broken packages

apt can’t find a set of package versions that satisfies all dependencies — usually mixed repositories or a package from another r…

E0373: closure may outlive the current functionRust

Rust: error[E0373]: closure may outlive the current function, but it borrows `v`, which is owned by the current function

A closure borrowing a local is passed somewhere that may outlive it (thread::spawn, tokio::spawn, returned closures).

E0277: the trait bound is not satisfiedRust

Rust: error[E0277]: the trait bound `Foo: Display` is not satisfied / `Rc<RefCell<T>>` cannot be sent between threads safely

A type doesn't implement a trait required by a function, macro or generic bound.

ssh port 22 Connection refusedLinux

ssh: connect to host x port 22: Connection refused

The server answered, but nothing is listening on the SSH port — sshd isn’t running, it uses another port, or a firewall actively…

ssh port 22 Connection timed outLinux

ssh: connect to host x port 22: Connection timed out

SSH packets get no reply — a firewall/security group drops them, the server is off, or the IP is wrong.

Temporary failure in name resolutionLinux

ping: google.com: Temporary failure in name resolution

The Linux host can’t resolve domain names — no working DNS server is configured or reachable.

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