Issue with sbt-web/sassify, sub-projects, and the Play dev server...

[mikesname]

Hi all,

I'm trying to update an app from 2.8.21 to 2.9.3 and while it's mostly pretty plain sailing I've come across an issue that's a bit of a blocker for me.

In a nutshell:

• my app uses SBT sub-projects
• it also uses the sbt-sassify plugin
• while I could change my SASS files and see the result in the browser with 2.8.21, in 2.9.3 I cannot

While changing the SASS assets does trigger a recompilation of the CSS, this does not seem to propagate from the sub-project to the root project. It only works if I do a full rebuild. At first I thought this was an SBT issue, but the latest SBT 1.10.0 and Play 2.8.21 works fine.

Does anyone recognise this issue, or have a sense if it's a Play thing, an sbt-sassify thing, an sbt-web thing or something else?

I have made a minimal project here to test things if that's of use: https://github.com/mikesname/sbt-sass-issue

[mkurz]

I would guess this could be caused by the fact that sbt-sassify 1.5.2 still uses sbt-web 1.4.x, whereas Play and basically all popular sbt-web plugins now use sbt-web 1.5.x. There is an open pull request which wasn't looked at by the maintainer yet: irundaia/sbt-sassify#53
Before there is no sbt-sassify release that is based on latest dependencies (=sbt-web 1.5.x) it's hard to tell what is causing this issue.

You could go ahead an build your own (or fork) sbt-sassify library with upgraded dependencies and see if then your problem still occurs.

[mikesname]

Thanks @mkurz, I'll try and figure that out. Seems like a likely culprit.

Update: I gave the open PR from @OlegYch a go locally, with the latest sbt-web (1.5.5) and unfortunately I'm still seeing this problem.

[mikesname]

I've done a bit more digging here and unless I've made a mistake this problem also affects at least sbt-less, sbt-uglify (both using sbt-web 1.5) and sbt-vuefy (on sbt-web 1.4), so perhaps it's a broader problem with Play 2.9 and sub-module projects? Worth a look perhaps, I am happy to put in an issue.