Next13 issue tracker cannot build due to prerender error

[Choongkyu]

when running either build script or vercel build on the Next13 issue tracker project, the following error is issued during static page generation:

info  - Collecting page data  
[=   ] info  - Generating static pages (2/3)[
  {
    extensions: { value: null, problems: [Array] },
    locations: [ [Object] ],
    message: 'Variable $issueNumber of type Int! was provided invalid value'
  }
]
Error: Error fetching GraphQL query 'IssueQuery' with variables '{"owner":"facebook","name":"relay","issueNumber":null}': [{"extensions":{"value":null,"problems":[{"path":[],"explanation":"Expected value to not be null"}]},"locations":[{"line":4,"column":3}],"message":"Variable $issueNumber of type Int! was provided invalid value"}]
    at networkFetch (/home/choongkyu/code/relay-examples/issue-tracker-next-v13/.next/server/chunks/963.js:93:15)
    at process.processTicksAndRejections (node:internal/process/task_queues:95:5)
    at async loadSerializableQuery (/home/choongkyu/code/relay-examples/issue-tracker-next-v13/.next/server/chunks/963.js:138:22)
    at async IssuePage (/home/choongkyu/code/relay-examples/issue-tracker-next-v13/.next/server/app/issues/[id]/page.js:398:28)
[Error: An error occurred in the Server Components render. The specific message is omitted in production builds to avoid leaking sensitive details. A digest property is included on this error instance which may provide additional details about the nature of the error.] {
  digest: '3066697309'
}

Error occurred prerendering page "/issues/[id]". Read more: https://nextjs.org/docs/messages/prerender-error
Error: Error fetching GraphQL query 'IssueQuery' with variables '{"owner":"facebook","name":"relay","issueNumber":null}': [{"extensions":{"value":null,"problems":[{"path":[],"explanation":"Expected value to not be null"}]},"locations":[{"line":4,"column":3}],"message":"Variable $issueNumber of type Int! was provided invalid value"}]
    at networkFetch (/home/choongkyu/code/relay-examples/issue-tracker-next-v13/.next/server/chunks/963.js:93:15)
    at process.processTicksAndRejections (node:internal/process/task_queues:95:5)
    at async loadSerializableQuery (/home/choongkyu/code/relay-examples/issue-tracker-next-v13/.next/server/chunks/963.js:138:22)
    at async IssuePage (/home/choongkyu/code/relay-examples/issue-tracker-next-v13/.next/server/app/issues/[id]/page.js:398:28)
info  - Generating static pages (3/3)

> Build error occurred
Error: Export encountered errors on following paths:
        /issues/[id]/page: /issues/[id]
    at /home/choongkyu/code/relay-examples/issue-tracker-next-v13/node_modules/next/dist/export/index.js:409:19
    at process.processTicksAndRejections (node:internal/process/task_queues:95:5)
    at async Span.traceAsyncFn (/home/choongkyu/code/relay-examples/issue-tracker-next-v13/node_modules/next/dist/trace/trace.js:79:20)
    at async /home/choongkyu/code/relay-examples/issue-tracker-next-v13/node_modules/next/dist/build/index.js:1398:21
    at async Span.traceAsyncFn (/home/choongkyu/code/relay-examples/issue-tracker-next-v13/node_modules/next/dist/trace/trace.js:79:20)
    at async /home/choongkyu/code/relay-examples/issue-tracker-next-v13/node_modules/next/dist/build/index.js:1258:17
    at async Span.traceAsyncFn (/home/choongkyu/code/relay-examples/issue-tracker-next-v13/node_modules/next/dist/trace/trace.js:79:20)
    at async Object.build [as default] (/home/choongkyu/code/relay-examples/issue-tracker-next-v13/node_modules/next/dist/build/index.js:66:29)
error Command failed with exit code 1.