Error map
E0369: binary operation cannot be applied to type Rust: error[E0369]: binary operation `+` cannot be applied to type `Foo` / cannot add `&str` to `&str`
Rust · layer 4, Application & API
Centre: this error. First ring: errors it is linked with (9). Outer ring: what those are linked with. Colours show the layer of a request each error belongs to. Click any dot to re-centre the map on it; hover to follow its connections. The centre dot opens the error page.
Directly related (9)
Rust: error[E0308]: mismatched types — expected `X`, found `Y`
A value’s type doesn’t match what the context expects — common with &str vs String, Option/Result vs plain values, and integer ty…
C++: error: no match for 'operator<<' (operand types are 'std::ostream' and 'X')
You used an operator on a type that does not define it — most often printing your own class with `
C++: error: ISO C++ forbids comparison between pointer and integer [-fpermissive]
You compared a string literal or pointer with a character or integer — typically `ch == "y"` instead of `ch == 'y'`.
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.
Rust: error[E0599]: no method named `push_str` found for struct `Vec<String>` in the current scope
The type doesn't have that method — wrong type, trait not in scope, or missing derive/feature.
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.
Rust: error[E0038]: the trait `Shape` cannot be made into an object (not dyn compatible)
You used `dyn Trait` for a trait whose methods aren't object-safe (generic methods, `Self` returns, `Sized`).
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: 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 (24)
AttributeError: 'X' object has no attribute 'y'
You accessed an attribute or method that doesn’t exist on that object type.
java.lang.ClassCastException: class A cannot be cast to class B
An object was cast to a type it isn’t.
TS7016: Could not find a declaration file for module 'x'. 'x.js' implicitly has an 'any' type.
The JavaScript package has no TypeScript types bundled and no @types package installed.
C++: error: no matching function for call to 'f(int, const char*)'
No overload of the function accepts the arguments you passed — wrong count, wrong types, or a missing conversion.
C++: error: call of overloaded 'f(int)' is ambiguous
Two or more overloads fit equally well, so the compiler refuses to guess which function you meant.
C++: error: cannot declare variable 'x' to be of abstract type 'Shape' (pure virtual functions)
You tried to create an object of a class that still has pure virtual functions; only a derived class that overrides all of them c…
C++: error: invalid conversion from 'const char*' to 'char*' [-fpermissive]
C++ forbids silently dropping `const` or converting between unrelated pointer types — typically a string literal assigned to `cha…
C++: error: 'string' does not name a type
Where the compiler expected a type, it found a name it does not know as one — a missing header, namespace, or class declared late…
C++: error: narrowing conversion of 'x' from 'int' to 'char' inside { } [-Wnarrowing]
Brace initialisation `{}` refuses conversions that can lose data, such as `double` to `int` or a runtime `int` to `char`.
Rust: error[E0004]: non-exhaustive patterns: `None` not covered
A `match` doesn't handle every possible value of the type.
Rust: error[E0061]: this function takes 2 arguments but 1 argument was supplied
A call has too few or too many arguments for the function signature.
Rust: error[E0282]: type annotations needed for `Vec<_>` / consider giving `x` an explicit type
The compiler can't infer a type from the available information.
Rust: error[E0425]: cannot find value `x` in this scope
The identifier (variable, function, constant) isn't defined where it's used.
Rust: error[E0432]: unresolved import `crate::utils` — maybe a missing crate `utils`?
A `use` path doesn't point to an existing module, crate or item.
Rust: error[E0608]: cannot index into a value of type `HashSet<i32>` / `String` cannot be indexed by `{integer}`
The type doesn't support `[]` indexing (or not with that index type).
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.
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.
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 `&`).
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…
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.
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).
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: 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.
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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