Bug: not able to serve built site in macos

[snowman]

Description

Error when running the command gatsby serve.

Steps to reproduce

  cd /tmp
  gatsby new global-styles https://github.com/gatsbyjs/gatsby-starter-hello-world
  cd global-styles
  gatsby build
  gatsby serve

Environment

System:
  OS: macOS 10.14.4
  CPU: (6) x64 Intel(R) Core(TM) i5-8500 CPU @ 3.00GHz
  Shell: 5.3 - /bin/zsh
Binaries:
  Node: 11.13.0 - ~/.nvm/versions/node/v11.13.0/bin/node
  Yarn: 1.15.2 - /usr/local/bin/yarn
  npm: 6.7.0 - ~/.nvm/versions/node/v11.13.0/bin/npm
Languages:
  Python: 3.7.3 - /Users/peng/.virtualenvs/python-dev/bin/python
Browsers:
  Chrome: 74.0.3729.131
  Safari: 12.1
npmPackages:
  gatsby: ^2.4.2 => 2.4.2 

[cluzier]

You're sure you're in the correct directory? I know in the reproduction steps you do cd tmp but is tmp really the right place? Just taking a shot in the dark.

[snowman]

sorry about missing one step.. you can see the current directory in the screenshot is global-styles.

[eclectic-coding]

I can confirm on my MacOS with the Hello-world start, the same result as you have described. However, the Default starter works fine.

[thomascorthouts]

I was able to reproduce as well, a quick check learned me that adding the default gatsby-*.js files made this one "serve-able" from localhost.

It seems like an empty gatsby-config.js is sufficient to make it work. No immediate idea on the origin of the issue, but just putting it here.

[eclectic-coding]

@thomascorthouts good point. the hello-world is a fairly blank starter and it makes since it would not serve in is fresh install state.

I wonder if it would better to include a gatsby-config.js file with the basic sitemetadata and no plugins for this starter?

[thomascorthouts]

@polishedwp indeed, it makes sense. The place it's used in the tutorial on the website, it's only ever been run in develop.

It might be a good addition to add a note that the serve part doesn't work in the starter docs or as you proposed to have a gatsby-config.js with basic data.

[thomascorthouts]

In version 2.3.36 of Gatsby, it still worked without a gatsby-config.js so it seems like a breaking change that could/should at least be resolved by adding a note about it somewhere.
I think it might be related to the #12128 pathPrefix PR somehow, in that it expects to at least have a config file.

[thomascorthouts]

In line 72 of serve.js it is introduced to const { pathPrefix: configPathPrefix } = config where if config would be null or undefined it would result in a TypeError: Cannot destructure property 'pathPrefix' of 'undefined' or 'null'. error.

[thomascorthouts]

This issue should have been fixed with gatsby: 2.4.3 and in the newest versions of the hello-world starter, there will also be an empty gatsby-config.js included. @Unmem if you would run into this issue again, please feel free to open a new issue.