AssertionError:Transformation for statement 'x = x + x' gave an unexpected result

I have a problem when brian2.test()

What you have aready tried

Expected output (if relevant)

Actual output (if relevant)

Full traceback of error (if relevant)

Hi @XiaoZhao. Thank you for the report. You can safely ignore this error, it is an issue with the specific formulation of the test and changes in sympy 1.30 (you could get rid of the error by downgrading the sympy version, but I don’t think it is worth it – there is no issue with Brian’s functionality, it is only that our test is not adapted). We have already fixed it in Brian’s development version (see b/t/test_codegen.py: fix 2.00000000000000 == 2 by emollier · Pull Request #1553 · brian-team/brian2 · GitHub), but we did not do a release since then.