Gemini CLI error
Gemini CLI: SyntaxError: Invalid regular expression flags
SyntaxError: Invalid regular expression flagsStatus: By designLast verified 1 documented fix3 sources
What it means
The CLI crashes on startup inside a dependency (for example node_modules/string-width/index.js) because the Node.js runtime is too old for the regex syntax it uses.
Causes
- Running on Node.js 18 (the report shows Node.js v18.20.4). Gemini CLI requires Node.js 20.0.0+ (installation docs; package engines "node": ">=20.0.0"). The minimum was raised to Node 20 in #3277.
How to fix it
- Fix 1.
Upgrade Node.js to version 20 or later, then reinstall. Maintainer skeshive in #14739: "Can you try updating to node version 20? Looks like you're on 18".
Terminalnpm install -g @google/gemini-cli@latest
More Gemini CLI errors
All 19 Gemini CLI errorsYou must be a named user on your organization's Gemini Code Assist Standard edition subscription to use this service. Please contact your administrator to request an entitlement to Gemini Code Assist Standard edition.Status: WorkaroundFailed to sign in. Message: Your current account is not eligible... because it is not currently available in your location.Status: By designFailed to sign in. Message: Request contains an invalid argumentStatus: WorkaroundUNABLE_TO_GET_ISSUER_CERT_LOCALLY or unable to get local issuer certificateStatus: WorkaroundThis account requires setting the GOOGLE_CLOUD_PROJECT or GOOGLE_CLOUD_PROJECT_ID env var. See https://geminicli.com/docs/get-started/authentication/#set-gcpStatus: By designInvalid Google Cloud Project ID: "<projectId>". The GOOGLE_CLOUD_PROJECT (or GOOGLE_CLOUD_PROJECT_ID) environment variable must be set to your string-based Project ID (e.g., "my-project-123"), not your numeric Project Number. Please update your environment variables.Status: By designFailed to login. Message: Precondition check failed.Status: Fixed in releaseYou are currently configured to use a Google Cloud Project but lack a Gemini Code Assist license. Please contact your administrator to request a license.Status: Workaround
Related reading
- Do Your Agent Hooks Fail Open? Claude Code vs Codex vs Cursor vs Gemini CLIA guard hook that crashes, times out or points at a missing script lets the tool call through by default in Claude Code. v2.1.295 adds onFailure: block. Here is what each coding agent does when your policy hook breaks, with real test runs.
- How to Keep API Keys Away From Your AI Coding Agent: Claude Code vs Codex vs Cursor vs Gemini CLIA deny rule on .env stops cat but not a Python one-liner. Here are the three layers that actually keep secrets out of a coding agent's context - file rules, environment scrubbing and credential masking - and what Claude Code, Codex, Cursor and Gemini CLI give you for each, with real test runs.
- Headless AI Coding Agents in CI: Claude Code, Codex CLI, Gemini CLI, and opencode ComparedHeadless AI coding agents in CI compared: Claude Code, Codex CLI, Gemini CLI, and opencode on invocation flags, sandboxing, auth, and output formats.
- Gemini CLI to Antigravity CLI Migration Guide: The June 18 DeadlineGemini CLI to Antigravity CLI migration guide: install, migrate config, update scripts and CI, and avoid the silent MCP failure that breaks tool calls.
- Gemini CLI Guide: 1M Token Context and Who Can Still Use ItGemini CLI puts a 1 million token context in your terminal but now only serves paid Gemini API, Vertex AI and Code Assist users. Setup and TypeScript workflow.
FAQ
What does "SyntaxError: Invalid regular expression flags" mean in Gemini CLI?
The CLI crashes on startup inside a dependency (for example node_modules/string-width/index.js) because the Node.js runtime is too old for the regex syntax it uses.
How do I fix "SyntaxError: Invalid regular expression flags"?
Upgrade Node.js to version 20 or later, then reinstall. Maintainer skeshive in #14739: "Can you try updating to node version 20? Looks like you're on 18".
Is this Gemini CLI error fixed?
Status: By design. Expected behavior, not a bug. The documented fixes change the setup that triggers it. Affected versions: Any release on Node.js below 20; Node 20 minimum since v0.1.10 (#3277); reported on 0.19.4 (#14739)
Sources
Last verified against 3 sources: official docs, maintainer replies and release notes.
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