We do not have this optional test dependency packaged yet.

--- icecream-2.1.8/tox.ini.orig
+++ icecream-2.1.8/tox.ini
@@ -6,8 +6,6 @@
     run unittest
 commands =
     python -m unittest -v
-deps =
-    sympy>=1.12
 
 [testenv:mypy]
 basepython = python3.9