# Ionic2 RC build problems

**URL:** <https://forum.ionicframework.com/t/ionic2-rc-build-problems/67298>\
**Category:** ionic-v3\
**Created:** [October 18, 2016, 3:28am UTC](https://forum.ionicframework.com/t/ionic2-rc-build-problems/67298 "2016-10-18T03:28:45Z")\
**Posts on this page:** 3\
**Page:** 1

<div class="post-metadata">

**Author:** ![Chrishawn](https://sea1.discourse-cdn.com/ionicframework/user_avatar/forum.ionicframework.com/chrishawn/32/101665_2.png) [@Chrishawn](https://forum.ionicframework.com/u/Chrishawn)\
**Post date:** [October 18, 2016, 3:28am UTC](https://forum.ionicframework.com/t/ionic2-rc-build-problems/67298/1 "2016-10-18T03:28:45Z")

</div>

ionic serve works fine,  
ionic build/emulate ios/android give me a main.js file with only this in it

```
!function(){"use strict"}();
//# sourceMappingURL=main.js.map

```

no errors shown in build log

---

<div class="post-metadata">

**Author:** ![ihadeed](https://sea1.discourse-cdn.com/ionicframework/user_avatar/forum.ionicframework.com/ihadeed/32/95258_2.png) [@ihadeed](https://forum.ionicframework.com/u/ihadeed)\
**Post date:** [October 18, 2016, 5:13am UTC](https://forum.ionicframework.com/t/ionic2-rc-build-problems/67298/2 "2016-10-18T05:13:32Z")

</div>

`ionic serve` runs the build process in development mode. `ionic build` runs it in production mode by default.

Can you try and run the following command to see if the issue has anything to do with prod/dev settings:

```auto
npm run build --dev

```

---

<div class="post-metadata">

**Author:** ![Chrishawn](https://sea1.discourse-cdn.com/ionicframework/user_avatar/forum.ionicframework.com/chrishawn/32/101665_2.png) [@Chrishawn](https://forum.ionicframework.com/u/Chrishawn)\
**Post date:** [October 18, 2016, 3:07pm UTC](https://forum.ionicframework.com/t/ionic2-rc-build-problems/67298/3 "2016-10-18T15:07:44Z")

</div>

good thought but same behavior

```
[10:05:03] ionic-app-scripts 0.0.30
[10:05:03] build dev started ...
[10:05:03] clean started ...
[10:05:03] clean finished in 8 ms
[10:05:03] copy started ...
[10:05:03] bundle dev started ...
[10:05:03] lint started ...
[10:05:03] copy finished in 196 ms
[10:05:04] lint finished in 1.14 s
[10:05:14] bundle dev finished in 11.00 s
[10:05:14] sass started ...
[10:05:15] sass finished in 955 ms
[10:05:15] build dev finished in 11.97 s

```

and then main.js seems unchanged at

```
!function(){"use strict"}();
//# sourceMappingURL=main.js.map
```