Radiance/gtk-3.20/gtk-main.css attempts to import nonexistent gnome-builder.css

Status changed to 'Confirmed' because the bug affects multiple users.

In /usr/share/themes/Radiance/gtk-3.20/apps create the link
sudo ln -s gedit.css gnome-builder.css
I did not see any difference in gedit, but the error message disappears.

Too have bug! Any solution?

I'm facing this problem when launching temrinus alpha 50

I'm with this same issue :/

This same issue show up *many* times during the upgrade from 16.04 to 18.04.

Many times.

The following provides a tentative FIX to the problem, assuming gedit is installed:
In /usr/share/themes/Radiance/gtk-3.20/apps create the link
sudo ln -s gedit.css gnome-builder.css

That fix is great, but not for those going through a new install of 18.04. I had to let the entire installation process finish before I could do anything about those messages at all, and their are dozens of them that go by. Given this is a new problem in this theme in 18.04 (at least as far as I know) and was definitely not present in 16.04, the issue should be addressed to avoid errors during installation of (or upgrade to) 18.04. Your fix can't be made until one of those is done.

this fix `In /usr/share/themes/Radiance/gtk-3.20/apps create the link
sudo ln -s gedit.css gnome-builder.css

this fix `In /usr/share/themes/Radiance/gtk-3.20/apps create the link
sudo ln -s gedit.css gnome-builder.css` is not working in ubuntu 18.04

I don't really understand why people are focusing on the ugly symlink workaround. It seems to me that the obvious immediate fix for the warning is to just delete the offending line from gtk-main.css. Of course, the deeper question is whether gnome-builder.css used to provide some important functionality, and whether that functionality needs to be replaced somehow.

I see this problem when running gio open of a Google maps location query URL.

I notice this happening in upgrades that relate to gtk-main.css. It might be worth looking at the history of changes to understand the change causing this to come in. If the line is not needed it should be deleted not because it is clearly harmful in some specific context so much as it is rather visible.

Just remove the line (73) in /usr/share/themes/Radiance/gtk-3.20/gtk-main.css, it's useless & not in ambiance..

I've hit this issue right after upgrading from 16.04 to 18.04

This bug was fixed in the package ubuntu-themes - 16.10+18.10.20181005-0ubuntu1

---------------
ubuntu-themes (16.10+18.10.20181005-0ubuntu1) cosmic; urgency=medium

  [ Khurshid Alam ]
  * Remove nonexistent gnome-builder.css (LP: #1773045)

  [ Marco Trevisan (Treviño) ]
  * Radiance: fix typo in assets link for focused buttons (LP: #1781736)
  * Radiance: Use scaled image for buttons border (LP: #1781736)
  * Ambiance, Radiance: don't use padding on window buttons for chromium
    (LP: #1782038)
  * Ambiance: use default foreground color for toolbar menus (LP:
    #1758841)
  * Ambiance, Radiance: show proper arrow in combobox (LP: #1743373)
  * Ambiance, Radiance: use default disabled color for actions headerbar
    buttons (LP: #1785699)
  * Ambiace, Radiance: use headerbar destructive-action definition for
    buttons
  * Ambiance, Radiance: fix list selected color for gnome-boxes (LP:
    #1761684)
  * Ambiance, Radiance: properly theme disabled and hovered accelerators
    (LP: #1795895)

 -- Marco Trevisan (Treviño) <mail@3v1n0.net> Fri, 05 Oct 2018 00:13:07 +0000

Hello Nate, or anyone else affected,

Accepted ubuntu-themes into bionic-proposed. The package will build now and be available at https://launchpad.net/ubuntu/+source/ubuntu-themes/16.10+18.04.20181005-0ubuntu1 in a few hours, and then in the -proposed repository.

Please help us by testing this new package. See https://wiki.ubuntu.com/Testing/EnableProposed for documentation on how to enable and use -proposed. Your feedback will aid us getting this update out to other Ubuntu users.

If this package fixes the bug for you, please add a comment to this bug, mentioning the version of the package you tested and change the tag from verification-needed-bionic to verification-done-bionic. If it does not fix the bug for you, please add a comment stating that, and change the tag to verification-failed-bionic. In either case, without details of your testing we will not be able to proceed.

Further information regarding the verification process can be found at https://wiki.ubuntu.com/QATeam/PerformingSRUVerification . Thank you in advance for helping!

N.B. The updated package will be released to -updates after the bug(s) fixed by this package have been verified and the package has been in -proposed for a minimum of 7 days.

16.10+18.04.20181005-0ubuntu1 fixed this issue for me

This bug was fixed in the package ubuntu-themes - 16.10+18.04.20181005-0ubuntu1

---------------
ubuntu-themes (16.10+18.04.20181005-0ubuntu1) bionic; urgency=medium

  [ Khurshid Alam ]
  * Remove nonexistent gnome-builder.css (LP: #1773045)

  [ Marco Trevisan (Treviño) ]
  * Radiance: fix typo in assets link for focused buttons (LP: #1781736)
  * Radiance: Use scaled image for buttons border (LP: #1781736)
  * Ambiance, Radiance: don't use padding on window buttons for chromium
    (LP: #1782038)
  * Ambiance: use default foreground color for toolbar menus (LP:
    #1758841)
  * Ambiance, Radiance: show proper arrow in combobox (LP: #1743373)
  * Ambiance, Radiance: use default disabled color for actions headerbar
    buttons (LP: #1785699)
  * Ambiance, Radiance: fix list selected color for gnome-boxes (LP:
    #1761684)
  * Ambiance, Radiance: properly theme disabled and hovered accelerators
    (LP: #1795895)

 -- Marco Trevisan (Treviño) <mail@3v1n0.net> Fri, 05 Oct 2018 00:08:30 +0000

The verification of the Stable Release Update for ubuntu-themes has completed successfully and the package has now been released to -updates. Subsequently, the Ubuntu Stable Release Updates Team is being unsubscribed and will not receive messages about this bug report. In the event that you encounter a regression using the package from -updates please report a new bug using ubuntu-bug and tag the bug report regression-update so we can easily find any regressions.