Error during bulk issue migration

[liamappelbe]

I was trying to move a few hundred issues from dart-lang/ffigen to dart-lang/native, but I got this error:

liama-macbookpro:repo_manage liama$ GITHUB_TOKEN=**** dart run bin/report.dart transfer-issues --source-repo dart-lang/ffigen --target-repo dart-lang/native --add-label package:ffigen --apply-changes
Create label package:ffigen
Transfer 100 issues from dart-lang/ffigen to dart-lang/native with id R_kgDOJMhU1Q
Unhandled exception:
OperationException(linkException: ServerException(originalException: null, originalStackTrace: null, parsedResponse: Response(data: null, errors: [GraphQLError(message: Something went wrong while executing your query. This may be the result of a timeout, or it could be a GitHub bug. Please include `BB1B:74EBF:DB1E19:ED8081:65554329` when reporting this issue., locations: null, path: null, extensions: null)], context: Context({ResponseExtensions: Instance of 'ResponseExtensions'}), response {data: null, errors: [{message: Something went wrong while executing your query. This may be the result of a timeout, or it could be a GitHub bug. Please include `BB1B:74EBF:DB1E19:ED8081:65554329` when reporting this issue.}]})), graphqlErrors: [])
#0      TransferIssuesCommand._transferMutation (package:repo_manage/issue_transfer.dart:236:32)
<asynchronous suspension>
#1      TransferIssuesCommand.transferIssues (package:repo_manage/issue_transfer.dart:188:31)
<asynchronous suspension>
#2      TransferIssuesCommand.transferAndLabelIssues (package:repo_manage/issue_transfer.dart:88:18)
<asynchronous suspension>
#3      TransferIssuesCommand.run (package:repo_manage/issue_transfer.dart:65:12)
<asynchronous suspension>
#4      CommandRunner.runCommand (package:args/command_runner.dart:212:13)
<asynchronous suspension>
#5      ReportCommandRunner.runCommand (package:repo_manage/src/common.dart:94:14)
<asynchronous suspension>
#6      main (file:///Users/liama/dev/dart_ecosystem/pkgs/repo_manage/bin/report.dart:11:8)
<asynchronous suspension>

Each time I ran the command, it would successfully transfer some issues, but this RPC still threw an error, so subsequent transfer batches didn't happen (and it didn't apply the label).

I was able to get it working by reducing the batch size from 100 to 10. I also increased the time between requests from 5 seconds to 30, but I don't know if that bit was necessary.

Side note: It might be nice to have an option to not transfer closed issues.