Error map
panic: test timed out after 10m0s Go: panic: test timed out after 10m0s — running tests: TestFoo (10m0s)
Go · layer 4, Application & API
Centre: this error. First ring: errors it is linked with (7). 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 (7)
Go: fatal error: all goroutines are asleep - deadlock!
Every goroutine is blocked waiting (on a channel, mutex or WaitGroup), so the program can never continue.
Go: cannot assign to struct field users["bob"].Age in map
Map values are not addressable, so you cannot modify a field of a struct stored directly in a map.
Go: panic: assignment to entry in nil map
You wrote to a map that was declared but never initialised.
Go: panic: sync: negative WaitGroup counter
`wg.Done()` was called more times than `wg.Add()`.
Go: listen tcp :8080: bind: address already in use
The port your Go server wants is already taken by another process (or a previous instance of your app).
Go: Get "https://api.example.com": context deadline exceeded (Client.Timeout exceeded while awaiting headers)
An operation did not finish before its context deadline or HTTP client timeout.
Go: assignment mismatch: 1 variable but os.Open returns 2 values
The number of variables on the left does not match the number of values the function returns.
Two steps away (21)
HTTP 409 Conflict
The request conflicts with the current state of the resource — e.g. a duplicate or an edit based on an outdated version.
java.util.ConcurrentModificationException
A collection was modified while being iterated (even in a single thread).
HTTP 412 Precondition Failed
A conditional request header (If-Match, If-Unmodified-Since) didn’t match the current state of the resource.
Go: ./main.go:5:2: "os" imported and not used
The file imports a package that no code in that file uses; Go treats this as a compile error, not a warning.
Go: ./main.go:12:2: undefined: handler
The compiler cannot find an identifier — a typo, a missing import, or it lives in another file/package that wasn't built.
Go: ./main.go:18:1: missing return
A function with a return type can reach its end without a return statement on some path.
Go: panic: runtime error: invalid memory address or nil pointer dereference
The program used a pointer, map, interface or struct field that was nil — usually an uninitialised value or an ignored error.
Go: panic: runtime error: index out of range [3] with length 3
Code accessed a slice, array or string element beyond its length.
Go: panic: runtime error: slice bounds out of range [:5] with capacity 3
A slice expression `s[a:b]` used bounds outside the slice's length or capacity.
Go: fatal error: concurrent map writes
Two goroutines wrote to the same map at the same time; the runtime detects it and aborts the program (not recoverable).
Go: fatal error: concurrent map read and map write
One goroutine read from a map while another wrote to it; the runtime aborts.
Go: panic: send on closed channel
A goroutine sent a value to a channel after it had been closed.
Docker: Bind for 0.0.0.0:80 failed: port is already allocated
Another container or host process already publishes that host port.
Error response from daemon: network X not found
The container or Compose project refers to a Docker network that doesn’t exist (any more).
Error response from daemon: Pool overlaps with other one on this address space
Docker tried to create a network whose subnet clashes with an existing Docker network (or a VPN/host route).
Go: context canceled (rpc error: code = Canceled desc = context canceled)
The context was cancelled before the operation finished — the caller gave up, the client disconnected, or a parent was cancelled.
Go: dial tcp 127.0.0.1:5432: connect: connection refused
Nothing is listening on the host and port your Go program tried to connect to.
Go: accept tcp [::]:8080: accept4: too many open files / open x: too many open files
The process reached its file-descriptor limit — usually leaked connections, files or response bodies.
Go: ./main.go:9:6: no new variables on left side of :=
`:=` declares variables, but all names on the left already exist in the same scope.
Go: invalid operation: a + b (mismatched types int and float64)
You combined two values of different types; Go never converts numeric types implicitly.
Go: cannot use "5" (untyped string constant) as int value in argument to f
A value's type is not assignable to the type required by the variable, parameter or return value.
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