* Francesco Poli (wintermute) <invernomuto@paranoici.org> [2016-02-22 22:41]:
Package: isympy
Version: 0.7.6.1-1
Severity: grave
Justification: renders package unusable
I think binary isympy lacks a dependency on python-sympy | 
python3-sympy. Without this dependency, installing it leaves the 
package in an unusable state:
[snip]
Hence, isympy should depend on python-sympy | python3-sympy. Please 
add this dependency.
Actually, isympy must depend only on python-sympy.  If python3-sympy 
is installed and python-sympy is not, then isympy fails, because of 
this:
  $ head -n 1 /usr/bin/isympy
  #!/usr/bin/python