Hi,
I'm using SageMath 9.4 on both Ubuntu 20.04 and 21.10. In Ubuntu 21.10, certain symbolic commands trigger a deprecation warning. This is not the case in Ubuntu 20.04.
Example 1:
sage: assume(x > 0)
/opt/SageMath/local/lib/python3.9/site-packages/sage/symbolic/expression_conversions.py:972:
DeprecationWarning: invalid escape sequence \|
"""
Example 2:
sage: bool(SR(2) < 0)
/opt/SageMath/local/lib/python3.9/site-packages/sage/symbolic/expression_conversions.py:972: DeprecationWarning: invalid escape sequence \|
"""
False
Note that SR(2) < 0 alone does not trigger the deprecation warning.
I am not sure, what causes this deprecation warning on Ubuntu 21.10.
Note that I have used the sage-9.4-Ubuntu_20.04-x86_64.tar.bz2 binaries to install SageMath 9.4 on both computers. The deprecation warning might not occur if SageMath is built from source code on Ubuntu 21.10. I have not tried this.