Fixing variables does not seems to be working with the Xpress solver. I used the example below (which was posted by someone on this forum) to create this MWE. I fix one of the variables as zero but it seems like JuMP is not passing it to the Xpress solver as you will see from the results. Running t…

Xpress Julia API has bug with fixing variables

odow June 16, 2022, 11:20pm 4

That looks like a bug in Xpress, not reflecting bounds on binary variables. Can you open an issue here? Issues · jump-dev/Xpress.jl · GitHub

Instead of Bin, I’d use:

@variable(model, 0 <= x <= 1, Int)

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