Better error printing; to_full_ring resets cached properties only if …

…going from qring to ring

syngular/ideal.py

@@ -319,8 +319,8 @@ def to_qring(self, other):
         self.ring = qring
 
     def to_full_ring(self):
-        self.delete_cached_properties()
         if isinstance(self.ring, QuotientRing):
+            self.delete_cached_properties()
             self.generators = (self.ring.ideal + self).generators
             self.ring = self.ring.ideal.ring
 

syngular/tools.py

@@ -20,7 +20,7 @@ def execute_singular_command(singular_command, timeout=syngular.TIMEOUT, verbose
     if 'halt' in output:
         raise TimeoutError(f"{timeout} s")
     if 'error' in output and 'groebner base computations with inexact coefficients can not be trusted due to rounding errors' not in output:
-        raise SingularException(output)
+        raise SingularException(f"{output}\n\n\nError occured while executing:\n{singular_command}")
     if '   ? `Q` is undefined' in output:
         output = output.replace("   ? `Q` is undefined", "")
         print("Singular Error: Q is undefined")