TypeError when projecting coordinate for geo addon

[stodge]

I'm trying to convert a DXF into GEOJSON. The DXF is purely cartesian in metres, with a pre-defined centroid. I'm using a function to project from cartesian using a custom projection:

# create custom projection
transformer = Transformer.from_crs(custom_proj.crs, "epsg:4326")

def project_coord(v1):
    v2 = transformer.transform(v1[1], v1[0])
    return ezdxf.math.Vec3(v2[0], v2[1], 0)

My code using the geo addon is:

    from ezdxf.addons import geo
    from ezdxf.math import Matrix44
    m = Matrix44()
    for e in msp:
        geo_proxy = geo.proxy(e)
        geo_proxy.wcs_to_crs(m)
        geo_proxy.map_to_globe(project_coord)

I'm getting an exception:

Traceback (most recent call last):
  File "dxftest.py", line 207, in <module>
    parse_dxf(args.site, args.input, args.output)
  File "dxftest.py", line 153, in parse_dxf
    geo_proxy.wcs_to_crs(m)
  File "/usr/local/lib64/python3.6/site-packages/ezdxf/addons/geo.py", line 315, in wcs_to_crs
    self.apply(crs.transform)
  File "/usr/local/lib64/python3.6/site-packages/ezdxf/addons/geo.py", line 336, in apply
    process(entity)
  File "/usr/local/lib64/python3.6/site-packages/ezdxf/addons/geo.py", line 333, in process
    entity[COORDINATES] = transform(entity[COORDINATES])
  File "/usr/local/lib64/python3.6/site-packages/ezdxf/addons/geo.py", line 331, in transform
    return [transform(c) for c in coords]
  File "/usr/local/lib64/python3.6/site-packages/ezdxf/addons/geo.py", line 331, in <listcomp>
    return [transform(c) for c in coords]
  File "/usr/local/lib64/python3.6/site-packages/ezdxf/addons/geo.py", line 331, in transform
    return [transform(c) for c in coords]
  File "/usr/local/lib64/python3.6/site-packages/ezdxf/addons/geo.py", line 331, in <listcomp>
    return [transform(c) for c in coords]
  File "/usr/local/lib64/python3.6/site-packages/ezdxf/addons/geo.py", line 331, in transform
    return [transform(c) for c in coords]
  File "/usr/local/lib64/python3.6/site-packages/ezdxf/addons/geo.py", line 331, in <listcomp>
    return [transform(c) for c in coords]
  File "/usr/local/lib64/python3.6/site-packages/ezdxf/addons/geo.py", line 331, in transform
    return [transform(c) for c in coords]
TypeError: 'float' object is not iterable

I'm using ezdxf 0.15.1 because of limitations of the system I'm developing under and can't change.

This occurs when it processes an ARC. Unfortunately I can't post the DXF, but I would appreciate any suggestions for any silly mistakes I'm making.

Thanks

[stodge]

I added a print statement inside the transform function in geo.py:

(transform) ([Vec2(-156.41, -2200.46), Vec2(-156.72, -2200.77), Vec2(-156.41, -2201.08), Vec2(-156.1, -2200.77), Vec2(-156.41, -2200.46)], [])

It receives coordinates of type Vec2, where it only supports Vec3. Hmmm.

[stodge]

I think an Arc entity is processed as a polygon, but perhaps it doesn't support Arcs.

[mozman]

Please create a minimal example which shows the issue and post the Python script and the zipped DXF file.