New sassc 3.6.1 is broken

[tim77]

Description of problem:
After sassc was updated to 3.6.1 packages depend on it won't compile anymore. This look like memory leak during build process.

Version-Release number of selected component (if applicable):
3.6.1

How reproducible:
Try to build yaru-theme for example.

Actual results:

ninja: Entering directory `noarch-redhat-linux-gnu'
[1/11] /usr/bin/sassc -a ../gnome-shell/src/gnome-shell.scss gnome-shell/src/gnome-shell.css
[2/11] /usr/bin/sassc -a ../gnome-shell/src/gnome-shell-high-contrast.scss gnome-shell/src/gnome-shell-high-contrast.css

and build stuck here until OOM killer happened.

Expected results:
Successful build as before and earlier versions.

Additional info:

• Koji task and full build info

[tim77]

Duplicate of sass/libsass#3033