How do I install the Diagnose Build Failure skill?

Run npx skillmds@latest add hostinger/diagnose-build-failure in your terminal (requires Node.js), paste this page's agent-chat prompt into Claude, Cursor, or any MCP-connected agent, or download the SKILL.md file and copy it into your agent's skills directory.

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Is Diagnose Build Failure free to use?

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Who published Diagnose Build Failure?

hostinger (@hostinger) published this skill. Their other Agent Skills are listed on their SkillMD profile.

Diagnose Build Failure by hostinger

Name: Diagnose Build Failure
Author: hostinger

File contents

Diagnose a Hostinger build failure

When to use

A deploy returned state failed.
The user reports the live site showing a build or runtime error.
The user asks "why did my deploy fail?".

Inputs to gather first

Domain.
The build uuid. If the user doesn't have it, call hosting_listJsDeployments (or hosting_listNodeJSBuildsV1) for the domain and filter states to failed.
For hosting_getNodeJSBuildLogsV1 you also need username — get it from hosting_listWebsitesV1.

Steps

Fetch the logs:
- hosting_showJsDeploymentLogs with domain + buildUuid for hosting_deployJsApplication builds.
- hosting_getNodeJSBuildLogsV1 with username + domain + uuid for archive builds.
- Both accept a start line (fromLine / from_line) — page through rather than requesting one enormous response.
Log content may contain ANSI escape sequences. Strip them before quoting.
Match against the signatures below, then report the most likely cause and a concrete fix.

Common failure modes

Signature in logs	Likely cause	Fix
`Error: Cannot find module 'X'`	Dependency missing from `package.json`, or it was only in `devDependencies`	Add it to `dependencies`, rebuild
`npm ERR! ERESOLVE`, `peer dep`	Dependency resolution conflict	Pin versions, or commit a lockfile so the server installs deterministically
`engine "node" is incompatible`, syntax errors in dependency code	Node version mismatch	Set `node_version` to `18`, `20`, `22`, or `24` on `hosting_createNodeJSBuildFromArchiveV1`, or fix `engines.node`
`sh: vite: not found`, `build script not found`	Wrong `build_script`, or the build tool is in `devDependencies` and wasn't installed	Override `build_script`; verify the script name in `package.json`
`no such file or directory` for `package.json`	Wrong project root in a monorepo	Set `root_directory` relative to `public_html`
Build succeeds but the site 404s	Wrong `output_directory`	Point `output_directory` at the real build output, relative to the root directory
`JavaScript heap out of memory`	Build exceeded the memory cap	Reduce the build footprint, or upgrade the plan
Wrong package manager resolving deps	Lockfile/manager mismatch	Set `package_manager` to `npm`, `yarn`, or `pnpm`
App builds and starts but gets no traffic	Port hardcoded	Bind to `process.env.PORT`
`undefined` config values at runtime	Missing environment variables	Environment variables are not settable via the API — the user must add them in hPanel

Report format

Cause — one sentence, quoting the exact log line.
Fix — the concrete code change or the tool call with the specific override.
Next action — offer to apply it, and wait for confirmation.

Do not

Do not guess a cause without quoting a log line.
Do not redeploy automatically — a redeploy overwrites what is live. Propose and wait.
Do not blame a "framework preset" — Hostinger has no preset parameter. The overrides in rules/nodejs-deployments.mdc are the real knobs.

---name: diagnose-build-failuredescription: Pull build logs from a failed Hostinger deployment and identify the failure mode (missing dependency, Node version mismatch, wrong output directory, dependency resolution conflict).---# Diagnose a Hostinger build failure## When to use- A deploy returned state `failed`.- The user reports the live site showing a build or runtime error.- The user asks "why did my deploy fail?".## Inputs to gather first1. Domain.2. The build `uuid`. If the user doesn't have it, call `hosting_listJsDeployments` (or `hosting_listNodeJSBuildsV1`) for the domain and filter `states` to `failed`.3. For `hosting_getNodeJSBuildLogsV1` you also need `username` — get it from `hosting_listWebsitesV1`.## Steps1. Fetch the logs: - `hosting_showJsDeploymentLogs` with `domain` + `buildUuid` for `hosting_deployJsApplication` builds. - `hosting_getNodeJSBuildLogsV1` with `username` + `domain` + `uuid` for archive builds. - Both accept a start line (`fromLine` / `from_line`) — page through rather than requesting one enormous response.2. Log content may contain ANSI escape sequences. Strip them before quoting.3. Match against the signatures below, then report the most likely cause and a concrete fix.## Common failure modes| Signature in logs | Likely cause | Fix ||---|---|---|| `Error: Cannot find module 'X'` | Dependency missing from `package.json`, or it was only in `devDependencies` | Add it to `dependencies`, rebuild || `npm ERR! ERESOLVE`, `peer dep` | Dependency resolution conflict | Pin versions, or commit a lockfile so the server installs deterministically || `engine "node" is incompatible`, syntax errors in dependency code | Node version mismatch | Set `node_version` to `18`, `20`, `22`, or `24` on `hosting_createNodeJSBuildFromArchiveV1`, or fix `engines.node` || `sh: vite: not found`, `build script not found` | Wrong `build_script`, or the build tool is in `devDependencies` and wasn't installed | Override `build_script`; verify the script name in `package.json` || `no such file or directory` for `package.json` | Wrong project root in a monorepo | Set `root_directory` relative to `public_html` || Build succeeds but the site 404s | Wrong `output_directory` | Point `output_directory` at the real build output, relative to the root directory || `JavaScript heap out of memory` | Build exceeded the memory cap | Reduce the build footprint, or upgrade the plan || Wrong package manager resolving deps | Lockfile/manager mismatch | Set `package_manager` to `npm`, `yarn`, or `pnpm` || App builds and starts but gets no traffic | Port hardcoded | Bind to `process.env.PORT` || `undefined` config values at runtime | Missing environment variables | Environment variables are not settable via the API — the user must add them in hPanel |## Report format1. **Cause** — one sentence, quoting the exact log line.2. **Fix** — the concrete code change or the tool call with the specific override.3. **Next action** — offer to apply it, and wait for confirmation.## Do not- Do not guess a cause without quoting a log line.- Do not redeploy automatically — a redeploy overwrites what is live. Propose and wait.- Do not blame a "framework preset" — Hostinger has no preset parameter. The overrides in `rules/nodejs-deployments.mdc` are the real knobs.

Frequently asked questions

Diagnose Build Failure