Work around lmfit limiting RBAnalysis to 10,000 Cliffords (backport #1595) #1597
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lmfit (through its asteval dependnecy) limits exponentiation in its expression models to 10,000. The limit is there to avoid denial of service attacks where user input could be substituted into a model and Python integers which are unbounded and could take up exponential amounts of memory. In qiskit-experiments, this case is not a concern. The workaround implemented here is to divide the exponential in the curve by 10 and then exponentiate the result by 10. This change allows up to 100,000 Cliffords which should be enough. The alternative workaround is to change `asteval.astutils.MAX_EXPONENT` to a sufficiently large value. Closes #1594 (cherry picked from commit 643c20a)
wshanks
approved these changes
Sep 5, 2025
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lmfit (through its asteval dependnecy) limits exponentiation in its expression models to 10,000. The limit is there to avoid denial of service attacks where user input could be substituted into a model and Python integers which are unbounded and could take up exponential amounts of memory. In qiskit-experiments, this case is not a concern. The workaround implemented here is to divide the exponential in the curve by 10 and then exponentiate the result by 10. This change allows up to 100,000 Cliffords which should be enough. The alternative workaround is to change
asteval.astutils.MAX_EXPONENTto a sufficiently large value.Closes #1594
This is an automatic backport of pull request #1595 done by Mergify.