taskScss does not handle SCSS imports

[AronNovak]

Steps to reproduce

$result = $this->taskScss([
      self::THEME_BASE . '/scss/style.scss' => self::THEME_BASE . '/css/style.css',
    ])
      ->setFormatter($formatter)
      ->importDir(['scss'])
      ->run();

scss/style.scss:

@import "variables";
@import "pages/homepage";

Expected behavior

The @import shall be resolved in the output CSS.

Actual behavior

The @import directive appears as-is in the compiled CSS.

System Configuration

php -v
PHP 7.2.19 (cli) (built: May 29 2019 07:14:35) ( NTS )
Copyright (c) 1997-2018 The PHP Group
Zend Engine v3.2.0, Copyright (c) 1998-2018 Zend Technologies
    with Zend OPcache v7.2.19, Copyright (c) 1999-2018, by Zend Technologies
    with Xdebug v2.7.2, Copyright (c) 2002-2019, by Derick Rethans

Fedora 29:

5.1.16-200.fc29.x86_64 #1

[AronNovak]

Likely root cause: leafo/scssphp#402

[AronNovak]

Actually the importPath wasn't properly defined, it was an incorrect relative path. With the absolute path, it works nicely.