error.cmd

$ rollup -c

src/index.js → dist/calendardates.cjs.js, dist/calendardates.esm.js...
[!] (commonjs plugin) SyntaxError: Unexpected token (8:20) in c:\misc\sources\Github\throwaway.CalendarDates\src\index.js
src\index.js (8:20)
 6:   // 4. getDateMatrixWithMetadataAsync
 7:
 8:   static monthTypes = {
                        ^
 9:     PREVIOUS: "previous",
10:     CURRENT: "current",

error An unexpected error occurred: "Command failed.
Exit code: 1
Command: C:\\WINDOWS\\system32\\cmd.exe
Arguments: /d /s /c rollup -c
Directory: c:\\misc\\sources\\Github\\throwaway.CalendarDates
Output:
".
info If you think this is a bug, please open a bug report with the information provided in "c:\\misc\\sources\\Github\\throwaway.CalendarDates\\yarn-error.log".
info Visit https://yarnpkg.com/en/docs/cli/run for documentation about this command.