Linux GTK3 Perimeters box only has '-' button

[fasaxc]

Version

2.3.0-alpha.2

Operating system type + version

Ubuntu 20.04

3D printer brand / version + firmware version (if known)

Prusa MK3/s

Behavior

On the Layers and Perimeters page, the "Perimeters" box has a - button next to it but there's no +. - works as expected but + seems like it should be there.

Project File (.3MF) where problem occurs

Upload a PrusaSlicer Project File (.3MF) (Plater -> Export plate as 3MF for Slic3r PE 1.41.2 and older, File -> Save / Save Project for PrusaSlicer, Slic3r PE 1.42.0-alpha and newer)
Images (PNG, GIF, JPEG), PDFs or text files could be drag & dropped to the issue directly, while all other files need to be zipped first (.zip, .gz)

[fasaxc]

Note: tried the build that was not marked GTK3 and that works fine.

GTK3 version emits errors like this:

(prusa-slicer:347661): Gtk-CRITICAL **: 09:58:39.779: gtk_box_gadget_distribute: assertion 'size >= 0' failed in GtkSpinButton

[pmjdebruijn]

2.3.0~alpha3+69~g932dfb4fc still has this issue

[YuSanka]

2.3.0~alpha3+69~g932dfb4fc still has this issue

You are right. Fixed with 172c1bb
Thanks.

[bubnikv]

Fixed in PrusaSlicer 2.3.0-alpha4. Closing.