thread() produces error

[koendv]

This works:
use <threadlib/threadlib.scad>
thread("G1/2-ext", turns=10);

This is fine, too:
use <threadlib/threadlib.scad>
bolt("M5", turns=10);

But this produces an error:
use <threadlib/threadlib.scad>
thread("M5", turns=10);

DEPRECATED: Using ranges of the form [begin:end] with begin value greater than the end value is deprecated.
Compiling design (CSG Products generation)...
ERROR: Unable to convert point at index 1 to a vec3 of numbers, in file .local/share/OpenSCAD/libraries/list-comprehension-demos/skin.scad, line 32
WARNING: PolySet has degenerate polygons
Geometries in cache: 3
Geometry cache size in bytes: 709224
CGAL Polyhedrons in cache: 0
CGAL cache size in bytes: 0
Compiling design (CSG Products normalization)...
Normalized CSG tree has 1 elements
Compile and preview finished.
Total rendering time: 0 hours, 0 minutes, 2 seconds

(tested on OpenScad 2019.05 and 2015.03-3)

[koendv]

My fault; have to add -ext to thread name. Closed.