Build: Race condition in yarn run createDlls

[shilman]

When i run yarn bootstrap --reset --core:

storybook info bootstrap Generate DLL (dll)
storybook info bootstrap dll
lerna notice cli v3.19.0
lerna notice filter including "@storybook/ui"
lerna info filter [ '@storybook/ui' ]
lerna info Executing command in 1 package: "yarn run createDlls"
lerna ERR! yarn run createDlls exited 1 in '@storybook/ui'
lerna ERR! yarn run createDlls stdout:
$ node -r esm ./scripts/createDlls.js
info Visit https://yarnpkg.com/en/docs/cli/run for documentation about this command.
lerna ERR! yarn run createDlls stderr:
/Users/shilman/projects/baseline/storybook/lib/ui/scripts/createDlls.js:1
import path from 'path';
SyntaxError: Unexpected identifier
    at new Script (vm.js:83:7)
error Command failed with exit code 1.
lerna ERR! yarn run createDlls exited 1 in '@storybook/ui'
error Command failed with exit code 1.

however, when i subsequently run yarn bootstrap --core it succeeds.
this is a small thing. but it's problem, because it adds an extra step to my release process, and i release all the time. it's my first time to encounter this, and i'm seeing it on both next and master.

Note: I just upgraded to yarn@1.21.1. I'm not sure if it's related.

[lmaze]

Same error with the yarn bootstrap --all command.

[shilman]

Shiver me timbers!! I just released https://github.com/storybookjs/storybook/releases/tag/v6.0.0-alpha.7 containing PR #9770 that references this issue. Upgrade today to try it out!

You can find this prerelease on the @next NPM tag.

Closing this issue. Please re-open if you think there's still more to do.

[shilman]

Yowza!! I just released https://github.com/storybookjs/storybook/releases/tag/v5.3.13 containing PR #9770 that references this issue. Upgrade today to try it out!