Based on the error traceback provided in the issue, I can understand the code structure. Let me analyze the problem:

1. The error occurs when passing empty lists `[], []` to `wcs.wcs_pix2world([], [], 0)`
2. The error `InconsistentAxisTypesError` occurs in the underlying wcslib C code at `wcsp2s()`
3. The issue is that empty arrays are being passed to the underlying C library without being checked first

Looking at the traceback:
- `wcs_pix2world` calls `_array_converter`
- `_array_converter` calls `_return_list_of_arrays`
- `_return_list_of_arrays` calls the lambda `func(xy, origin)` which is `self.wcs.p2s(xy, o)['world']`
- The C library fails because it receives empty coordinates

The fix should check for empty arrays early in `_array_converter` and return empty arrays immediately without calling the underlying C library.

Based on the traceback line numbers and the typical structure of astropy's WCS code, the fix should be in the `_array_converter` method to handle empty input arrays by returning empty output arrays before calling the underlying transformation function.

Here's the patch:

--- a/astropy/wcs/wcs.py
+++ b/astropy/wcs/wcs.py
@@ -1222,6 +1222,12 @@ class WCS(WCSBase):
             if ra_dec_order and sky == 'input':
                 xy = self._denormalize_sky(xy)
+            # If the input is empty, return empty output immediately
+            # without calling the underlying C library which can't handle empty arrays
+            if len(xy) == 0:
+                return xy
+
             output = func(xy, origin)
             if ra_dec_order and sky == 'output':
                 output = self._normalize_sky(output)