# Need to rebuild app after changing app.yml?

**URL:** <https://meta.discourse.org/t/need-to-rebuild-app-after-changing-app-yml/41370>\
**Category:** Self-hosting\
**Created:** [3월 21, 2016, 3:10오후 UTC](https://meta.discourse.org/t/need-to-rebuild-app-after-changing-app-yml/41370 "2016-03-21T15:10:59Z")\
**Posts on this page:** 3\
**Page:** 1

<div class="post-metadata">

**Author:** ![JimmyX](https://sea3.discourse-cdn.com/meta/user_avatar/meta.discourse.org/jimmyx/32/52302_2.png) [@JimmyX](https://meta.discourse.org/u/JimmyX)\
**Post date:** [3월 21, 2016, 3:10오후 UTC](https://meta.discourse.org/t/need-to-rebuild-app-after-changing-app-yml/41370/1 "2016-03-21T15:10:59Z")

</div>

If using the Virtual Box (not docker) is there a need to “rebuild the app” after changing app.yml?

I actually copied some files over from the docker install because the file app.yml (taken from standalone.yml) was not there.

Perhaps I am screwing things up.

---

<div class="post-metadata">

**Author:** ![fefrei](https://sea3.discourse-cdn.com/meta/user_avatar/meta.discourse.org/fefrei/32/119538_2.png) [@fefrei](https://meta.discourse.org/u/fefrei)\
**Post date:** [3월 21, 2016, 7:57오후 UTC](https://meta.discourse.org/t/need-to-rebuild-app-after-changing-app-yml/41370/2 "2016-03-21T19:57:16Z")

</div>

Wait – are you running a development install? These don’t use container definitions.

Are you trying to develop Discourse, or do you want to run it?

---

<div class="post-metadata">

**Author:** ![JimmyX](https://sea3.discourse-cdn.com/meta/user_avatar/meta.discourse.org/jimmyx/32/52302_2.png) [@JimmyX](https://meta.discourse.org/u/JimmyX)\
**Post date:** [3월 22, 2016, 7:42오전 UTC](https://meta.discourse.org/t/need-to-rebuild-app-after-changing-app-yml/41370/3 "2016-03-22T07:42:51Z")

</div>

I want to develop.

I was confused trying to set up SMTP so I could create (and then email confirm) a new user. The docs talk about app.yml which comes from standalone.yml. These files are not in the developer install. So I grabbed them from the docker install and things went downhill from there.

What I needed instead was to run

bundle exec sidekiq \>& /dev/null &  
mailcatcher --http-ip=0.0.0.0

Then in a browser, go to [http://localhost:4080](http://localhost:4080). Sent emails will be received by mailcatcher and shown in its web ui. When you catch the email with confirmation link change localhost:3000 … to localhost:4000 … and paste that into the browser. It was as simple and intuitive as that 😉