Semantic-ui: [Build] Upgrading from 2.3 to 2.4 breaks the build

[franckboudraa]

Steps

• Install Semantic-UI 2.3.1 to root/src/semantic/
• Build with gulp build in root/src/semantic/
• Copy content of gist : https://gist.github.com/franckboudraa/0ab22ff1e29581c04041496aa54774fd
• Ok, the page is correctly displayed.
• Drop the dist/ folder in root/src/semantic/
• Update Semantic-UI to 2.4.2
• Build with gulp build in root/src/semantic/
• The page is no longer displayed correctly

Expected Result

Actual Result

Version

2.4.2

Testcase

No problem on 2.4.2 fresh install, only when upgrading from 2.3 to 2.4

[xeophin]

Happened to me as well. Upon checking my theme.config file, I realised that it didn't contain the new placeholder element, and added it between @loader and @rail, like this:

@loader     : 'default';
@placeholder: 'default';
@rail       : 'default';

Then the build process work again.

I guess the theme.config file isn't touched during updates, therefore missing the new component?

[franckboudraa]

Awesome, thank you @xeophin !

[reallistic]

Just happened to me. FWIW, the plumber error config seems to try to alert you of this but it is configured to check line 5 instead of line 9.

You can see this here: https://github.com/Semantic-Org/Semantic-UI/blob/52922d1e5cc78c370ae1458225c740a83028c249/tasks/config/tasks.js#L96-L103

The error I received (after manually logging it) is for line 9:

error { [Error: Recursive variable definition for @placeholder in file semantic/src/theme.less line no. 9]