related to #267

actually it runs on my computer.

sandbox/bug_267.py

@@ -0,0 +1,21 @@
+#!/usr/bin/env python
+import sys
+import numpy
+
+import fabio
+from pyFAI.calibration import calib, get_detector
+from pyFAI.calibrant import ALL_CALIBRANTS
+
+def get_calibrant(calibrant_name):
+    return ALL_CALIBRANTS[calibrant_name]
+
+def calibration(img, calibrant_name, detector_name, wavelength):
+    calibrant = get_calibrant(calibrant_name)
+    calibrant.wavelength = wavelength
+    detector = get_detector(detector_name)
+    calib(img, calibrant, detector)
+
+if __name__ == "__main__":
+    img = fabio.open(sys.argv[1]).data
+    print(sys.argv)
+    calibration(img, *sys.argv[2:])