ErrLookup › facebook/flow

facebook/flow

Adds static typing to JavaScript to improve developer productivity and code quality. · Rust · 1,903 source files

Analyzed at 21c11b2ead on 2026-09-16. 166 documented errors.

Code / Message	Type	Severity	Tags
Internal Error: Tried to add_declared_private with outside…	panic	error	flow-parser, internal-invariant, panic, class-scope, private-fields
Skipping_arrow_function	console	warning	codemod, annotate-exports, arrow-function, warning, skipped-annotation
Attempted to insert a statement into	validation	error	flow, flow-transform, codemod, statement-anchor, ast-mutation
failed to write json errors	panic	error	rust, flow-cli, stdout, broken-pipe, json, panic
failed to spawn flow_server_main thread	panic	critical	thread-spawn, resource-limits, server-startup, stack-size, panic
failed to dup server->monitor channel	panic	critical	monitor, try-clone, fd-exhaustion, socket, startup, panic
cached canonicalize failure	exception	error	filesystem, canonicalize, cache, not-found, rust
check-contents input should be readable	panic	error	check-contents, file-io, server, panic, utf8
failed to spawn the command executor	panic	critical	thread-spawn, orchestrator, server-startup, resource-limits, panic
failed to spawn flow_cli_main thread	panic	error	windows, thread, stack-size, memory, spawn, panic
failed to spawn init thread	panic	critical	thread-spawn, resource-limits, server-startup, initialization, panic
Tried to remove from parent of type . However can only be…	validation	error	flow, flow-transform, codemod, remove-node, identifier, ast-mutation
failed to spawn connect_and_make_request_timed thread	panic	error	thread, spawn, resource-limits, timeout, panic, mpsc
type-at-pos: server payload is valid JSON	panic	error	json, serialization, server-client, type-at-pos
content_of_file_input_unsafe: failed to read file	panic	error	file-io, file-input, panic, utf8, server-utils
To be able to build a thread pool	panic	critical	rayon, thread-pool, resource-limits, stack-size, startup, panic
Peeking current location when not available	panic	error	flow-parser, loc, assertion, start-of-input, lookahead
clone of socket stream for read failed	panic	error	monitor, try-clone, fd-exhaustion, socket-accept, panic
failed to dup monitor->server channel	panic	critical	monitor, try-clone, fd-exhaustion, socket, startup, panic
socket path has no basename	validation	error	unix-socket, path-validation, invalid-input, rust
${message}	exception	error	flow, flow-transform, codemod, ast-mutation, mutation-tracking
Failed to create tokio runtime	panic	critical	tokio, runtime, server-startup, resource-limits, panic
max_workers should be positive	panic	error	configuration, flowconfig, max-workers, server-startup, validation
Monitor_died (EPIPE)	panic	critical	broken-pipe, epipe, monitor, server-lifecycle, ipc
failed to flush cli errors	panic	error	stdout, broken-pipe, io-flush, cli
failed to spawn recheck_cancel_monitor thread	panic	error	thread-spawn, recheck, file-watcher, resource-limits, panic
Daemon::spawn: timed out reading token from child	exception	error	daemon, handshake, timeout, tcp, rust
only 7bit ascii allowed in	panic	error	lsp, file-url, unicode, percent-encoding, paths, i18n
Type size limit exceeded	error_code	error	rust, type-checker, resource-limit, recursion
Realpath failed for existent path	panic	error	filesystem, symlink, realpath, race-condition
failed to spawn connection thread	panic	critical	thread-spawn, connection-handling, resource-limits, server-crash, panic
timed out connecting to named pipe	exception	error	windows, named-pipe, timeout, connect, rust
Unexpected function parameter	exception	error	typescript, flow, api-translator, unsupported-syntax, ast
failed to spawn wait_for_anything thread	panic	error	thread-spawn, async, file-watcher, resource-limits, panic
lock file is already held	exception	error	server, lock-file, single-instance, flock, rust
mkdir_no_fail( )	panic	error	filesystem, temp-dir, permissions, flowlib, mkdir, startup
Daemon::from_channel: bincode deserialize	panic	error	rust, bincode, tcp, daemon, timeout, eof
hh_load_heap: invalid magic number	exception	error	heap, serialization, magic-number, corruption, rust
Cannot get hostname	panic	error	hostname, flowconfig, rollout, environment
Cannot perform a remove mutation on node of type	validation	error	flow, flow-transform, codemod, remove-node, ast-mutation
flow-remove-types: the "checkPragma" option has been…	validation	error	flow, flow-remove-types, options, migration, breaking-change
; additionally failed to stop Flow	exception	error	runtests, autofix, compound-error, server-cleanup, rust
failed to flush spinner status	panic	error	stderr, broken-pipe, spinner, server-busy
failed to read stdin	panic	error	cli, stdin, utf-8, panic, rust
flow-remove-types: includes and excludes must be RegExp or…	validation	error	flow, flow-remove-types, require-hook, glob, regexp, config
import/export cannot be inserted into a	validation	error	flow, flow-transform, codemod, imports, module-declaration, ast-mutation
Daemon::spawn: timed out waiting for child to connect	exception	error	daemon, spawn, timeout, tcp, rust
CommonJS exports cannot be combined with ES module exports.	exception	error	javascript, typescript, flow, libdef, module-exports, translation
Unterminated quote in argument string	validation	error	runtests, exec-file, quoting, parse-error, rust
unable to resolve scope	exception	error	flow, api-translator, scope, ast, parent-pointers
Expected to find a valid statement parent, but found a…	exception	error	flow, flow-transform, codemod, statement-anchor, ast-mutation
failed to write cli errors	panic	error	rust, flow-cli, stdout, broken-pipe, diagnostics, panic
Popping lex mode from empty stack	panic	error	flow-parser, lexer, stack-underflow, panic, lex-mode
Can't decode daemon parameters	panic	critical	daemon, serialization, version-mismatch, corruption
failed to write errors	panic	error	stdout, broken-pipe, json, io-error, panic, check-contents
handler existed during typed validation	panic	critical	rust, lsp, invariant, hashmap, race-condition
failed to get executable path	panic	error	build-id, current-exe, procfs, deploy
failed to spawn server daemon	panic	critical	server, daemon, lock, process-spawn, startup, monitor
failed to spawn glean_runner_visit_timeout thread	panic	error	thread, spawn, resource-limits, glean, timeout, panic
failed to get current directory	panic	error	cwd, filesystem, getcwd, paths, panic
flow.js wasm is still loading; await flow.ready first.	exception	error	wasm, async, initialization, race-condition, flow-js
failed to flush stdout	panic	error	stdout, broken-pipe, flush, save-state, panic
failed to write codemod output	panic	error	filesystem, codemod, file-write, permissions
failed to write status	panic	error	stderr, terminal-io, panic, status-output
Could not find target in array of	validation	error	flow, flow-transform, codemod, statement-anchor, stale-reference, ast-mutation
Expected to find the target	exception	error	flow, flow-transform, codemod, statement-anchor, stale-reference, ast-mutation
failed to flush json errors	panic	error	rust, flow-cli, stdout, broken-pipe, flush, panic
File_key: project_root has not been set	panic	error	rust, global-state, initialization, programmer-error
Daemon::to_channel: flush failed	panic	error	daemon, ipc, flush, broken-pipe
import/export cannot be replaced into a	validation	error	flow, flow-transform, codemod, imports, module-declaration, ast-mutation
failed to clear spinner line	panic	error	stderr, broken-pipe, spinner, connect
Daemon::set_context: bincode serialize context	panic	error	rust, bincode, tempfile, disk-full, io, daemon
failed to write spinner status	panic	error	stderr, terminal-io, panic, spinner, progress
flow-dot-js wasm requires crypto.getRandomValues	exception	error	flow, wasm, crypto, webcrypto, environment, polyfill
flow.js wasm export is unavailable	exception	error	flow, wasm, version-mismatch, exports, module-loading
an active transaction may only be committed once	panic	error	transaction, invariant, double-commit, panic, state-management
socket timeout	exception	error	socket, timeout, read-write, rust
recheck failed	panic	error	codemod, recheck, concurrent-modification, canceled
Daemon::flush failed	panic	error	rust, tcp, flush, io, daemon
Parser out of memory	exception	error	flow, parser, wasm, out-of-memory, large-files
Failed to query mergebase: unable to find vcs	panic	critical	watchman, vcs, git, environment, file-watcher, mergebase
invalid file index	exception	error	heap, serialization, corruption, index-out-of-bounds, rust
updatePendingStatements: Variable for dependency	exception	error	flow, api-translator, libdef, scope, dependency-resolution
failed to spawn LSP log flusher	panic	critical	thread-spawn, resource-limits, lsp, panic, startup
failed to write vim/emacs errors	panic	error	stdout, broken-pipe, vim, emacs, editor-integration, panic
Unexpected selector	exception	error	flow, flow-transform, esquery, selector, visitor, node-types
updatePendingStatements: Variable parent of	exception	error	flow, api-translator, libdef, scope, implicit-globals
Failed to open log file	panic	error	logging, daemon, filesystem, permissions, server-startup, temp-dir
hh_load_heap: invalid shard count	exception	error	heap, serialization, sharding, format-version, rust
Daemon::to_channel: bincode serialize	panic	error	daemon, bincode, ipc, broken-pipe
failed to read input file	panic	error	rust, flow-cli, filesystem, utf-8, file-not-found, panic
Replacement_printer: Input file	panic	error	codemod, file-io, replacement-printer, ast-diff, race-condition
Expected to find the	validation	error	flow, flow-transform, codemod, replace-node, stale-reference, ast-mutation
failed to decompress	panic	error	rust, lz4, compression, corruption, saved-state
failed to flush success output	panic	error	rust, flow-cli, stdout, broken-pipe, flush, panic
init failed	panic	critical	server, initialization, flowconfig, startup, type-service
Daemon child: failed to connect to parent out-socket (child…	panic	critical	daemon, socket, connect, loopback, spawn
flowImportTo: Unexpected transform result.	exception	error	flow, api-translator, ast, transform, imports
Invalid position: ; column: }}	panic	error	positions, lsp, off-by-one, validation, offsets, race-condition
Syntax error in selector	exception	error	flow, flow-transform, esquery, selector, syntax-error, visitor