Intermittent TS2345 from tsgo --build when a paths-aliased module also has @types/* declarations

This is a reduced repro for an intermittent tsgo --build type-check failure we started seeing after switching CI to the TS Go beta. Our full monorepo fails somewhere in the range of 1-5% of runs, but this repro fails around 30-50% of clean builds. tsc --build (TypeScript 6) passes consistently.

Setup:

• tsconfig.paths aliases react and react-dom to preact/compat.
• react, react-dom, and @types/react are also installed in node_modules.
• The repro passes Preact-typed components into @tiptap/react APIs. TipTap's .d.ts files import react, which trace resolution shows resolving to preact/compat; failing runs still report assignability errors involving @types/react declarations.

Expected behavior

tsgo --build schema/tsconfig.json should match tsc --build schema/tsconfig.json.

Actual behavior

Starting from a clean build state, tsgo --build schema/tsconfig.json reports TS2345 at the TipTap renderer call sites on roughly 40% of runs.

tsgo --build schema/tsconfig.json --singleThreaded passes 100/100.

A single invocation without first deleting .tsbuildinfo will not show the flake. repeat.sh runs --clean then --build each iteration.

Reproduce

npm ci
npm run tsgo:repeat           # default tsgo (100 runs)
npm run tsgo:repeat:single    # tsgo --singleThreaded (100 runs)
npm run tsc:repeat            # tsc control (100 runs)

Results

All rows: 100 iterations of --clean then --build via repeat.sh. The tsgo range spans multiple runs.

harness invocation	fails / 100
bash repeat.sh tsc	0
bash repeat.sh tsgo	30–50
bash repeat.sh tsgo --singleThreaded	0

Error sample

From evidence/sample-failure.txt:

schema/node-view.ts(5,32): error TS2345: Argument of type 'ComponentType<ReactNodeViewProps>' is not assignable to parameter of type 'ComponentType<ReactNodeViewProps<HTMLElement>>'.
  Type 'ComponentClass<ReactNodeViewProps, {}>' is not assignable to type 'ComponentType<ReactNodeViewProps<HTMLElement>>'.
    Type 'ComponentClass<ReactNodeViewProps, {}>' is not assignable to type 'ComponentClass<ReactNodeViewProps<HTMLElement>, any>'.
      Types of property 'contextType' are incompatible.
        Type 'preact.Context<any> | undefined' is not assignable to type 'React.Context<any> | undefined'.
          Type 'preact.Context<any>' is not assignable to type 'React.Context<any>'.
            Types of property 'Provider' are incompatible.
              Type 'preact.Provider<any>' is not assignable to type 'React.Provider<any>'.
                Property '$$typeof' is missing in type 'Provider<any>' but required in type 'ProviderExoticComponent<ProviderProps<any>>'.
schema/ref-view.ts(5,28): error TS2345: Argument of type 'ForwardRefExoticComponent<RefAttributes<RefViewHandle>>' is not assignable to parameter of type 'ComponentType<RefViewHandle, RefAttributes<RefViewHandle>>'.
  Property '$$typeof' is missing in type 'ForwardRefExoticComponent<RefAttributes<RefViewHandle>>' but required in type 'ForwardRefExoticComponent<Omit<RefAttributes<RefViewHandle>, "ref"> & RefAttributes<RefViewHandle>>'.

• node-view.ts exercises ReactNodeViewRenderer(ComponentType<ReactNodeViewProps>).
• ref-view.ts exercises the same identity split through new ReactRenderer(...) with a forwardRef-typed component.

Within a single failing run, one or both call sites may be flagged. The React.Context<any> reference above sometimes appears fully-qualified:

import("<repo>/node_modules/@types/react/index").Context<any>

Other tests/behavior observed

Tried a few modifications to the setup, each over 30 iterations.

Fixes the failure (0 / 30):

• Remove @types/react from node_modules.
• Collapse all source to a single tsconfig with no project references and no --build.

Still flakes:

• Add "types": [] to tsconfig-base.json: 15 failures / 30.
• Reduce to one call site (delete schema/ref-view.ts): 4 failures / 30, lower rate.

tsc --build schema/tsconfig.json passes under every condition above.

Module resolution evidence

In the trace runs we collected, both tsc and tsgo resolve @tiptap/react's import 'react' to node_modules/preact/compat/src/index.d.ts. evidence/tsgo-react-resolution.log is from a --traceResolution invocation that exited non-zero with TS2345 errors. Full traces: npm run trace:tsc, npm run trace:tsgo.

Environment

OS:         darwin arm64 (Darwin 25.4.0)
CPU cores:  14
node:       v20.18.0
npm:        10.8.2
tsc:        6.0.3
tsgo:       7.0.0-dev.20260519.1   (@typescript/native-preview)

preact            10.29.1
react             18.3.1
@types/react      18.3.28
@tiptap/core      2.27.2
@tiptap/react     2.27.2

Layout

.
├── package.json
├── package-lock.json
├── tsconfig-base.json
├── lib/
│   ├── tsconfig.json
│   ├── components.tsx            # NodeView (ComponentType<ReactNodeViewProps>) + RefView (forwardRef)
│   └── views.ts                  # `Views` view-contract type
├── schema/
│   ├── tsconfig.json             # ← the failing build target
│   ├── node-view.ts              # ReactNodeViewRenderer(views.NodeView)
│   └── ref-view.ts               # new ReactRenderer(views.RefView, …)
├── repeat.sh                     # 100-iter harness; takes `tsgo` (default) or `tsc` and extra flags
└── evidence/
    ├── sample-failure.txt
    ├── tsc-react-resolution.log
    └── tsgo-react-resolution.log

tsconfig-base.json:

{
  "compilerOptions": {
    "target": "es2020",
    "module": "commonjs",
    "jsx": "react-jsx",
    "jsxImportSource": "preact",
    "strict": true,
    "skipLibCheck": true,
    "incremental": true,
    "paths": {
      "react": ["./node_modules/preact/compat/"],
      "react/jsx-runtime": ["./node_modules/preact/jsx-runtime"],
      "react-dom": ["./node_modules/preact/compat/"],
      "react-dom/*": ["./node_modules/preact/compat/*"]
    }
  }
}

Failure output: failures/ (gitignored), with the first failure copied to failures/FIRST_FAILURE.out.