Theme is not a map.

[convini-kat]

Issue type

I'm submitting a ... (check one with "x")

• bug report
• feature request

Issue description

Current behavior:
After trying to register a custom theme with I get the following error when running ng serve

✘ [ERROR] $map: nb-register-theme ((color-primary-300: #56D1A4), default, default) is not a map.
   
41 │   $theme: map.get(theming-variables.$nb-themes, $name);
              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   
  node_modules/@nebular/theme/styles/core/theming/_register.scss 41:11  nb-get-registered-theme()
  node_modules/@nebular/theme/styles/core/theming/_install.scss 126:55  nb-install-global-with-css-props()
  node_modules/@nebular/theme/styles/core/theming/_install.scss 145:5   nb-install()
  src/app/@theme/styles/styles.scss 29:1                                root stylesheet [plugin angular-sass]

Expected behavior:

Variables, defined in nb-register-theme should be applied to the parent theme. ng serve should run without errors.

Steps to reproduce:

Imported nebular theme into my themes.scss and registered a theme, followed by the Docs.

Related code:

themes.scss

@import '@nebular/theme/styles/theming';
@import '@nebular/theme/styles/themes';

$nb-themes: nb-register-theme ( (
        color-primary-300: $brand-color-primary
) , default, default);

styles.scss

@use 'themes' as *;

@use '@nebular/theme/styles/globals' as *;
@import '@nebular/theme/styles/core/mixins';
@import '@nebular/auth/styles/globals';
@import 'bootstrap/scss/bootstrap';
@import 'bootstrap/scss/functions';
@import 'bootstrap/scss/variables';
@import 'bootstrap/scss/mixins';
@import 'bootstrap/scss/grid';
@import './pace.theme';

@include nb-install() {

  // framework global styles
  @include nb-theme-global();
  @include nb-auth-global();

  // loading progress bar
  @include ngx-pace-theme();
}

Other information:

npm, node, OS, Browser

yarn version: 1.22.19
node Version: v18.17.1
macOS Sonoma (14.1)

Angular, Nebular

@angular/cdk@16.2.12
@angular/cli@16.2.11
@angular/animations@16.2.12
@angular/common@16.2.12
@angular/core@16.2.12
@angular/compiler-cli@16.2.12
@angular/compiler@16.2.12
@angular/forms@16.2.12
@angular/language-service@16.2.12
@angular/localize@16.2.12
@angular/platform-browser@16.2.12
@angular/platform-browser-dynamic@16.2.12
@angular/router@16.2.12
nebular-icons@1.1.0
@nebular/theme@12.0.0
@nebular/auth@12.0.0
@nebular/eva-icons@12.0.0