Improve error msg for UnitVector3d.__getstate__

lsst · Jul 24, 2018 · 0e48d00 · 0e48d00
1 parent e61e6fe
commit 0e48d00
Showing 1 changed file with 3 additions and 1 deletion.
diff --git a/python/lsst/sphgeom/unitVector3d.cc b/python/lsst/sphgeom/unitVector3d.cc
@@ -22,6 +22,7 @@
 #include "pybind11/pybind11.h"
 
 #include <memory>
+#include <string>
 
 #include "lsst/sphgeom/Angle.h"
 #include "lsst/sphgeom/LonLat.h"
@@ -120,7 +121,8 @@ PYBIND11_MODULE(unitVector3d, mod) {
     cls.def(py::pickle([](UnitVector3d const &self) { return py::make_tuple(self.x(), self.y(), self.z()); },
                        [](py::tuple t) {
                            if (t.size() != 3) {
-                               throw std::runtime_error("Invalid state!");
+                               throw std::runtime_error("Tuple size = " + std::to_string(t.size()) +
+                                                        "; must be 3 for a UnitVector3d");
                            }
                            return new UnitVector3d(UnitVector3d::fromNormalized(
                                    t[0].cast<double>(), t[1].cast<double>(), t[2].cast<double>()));