binarySearch (from algorithm) not always working

[Stash]

Trying to fix a bug and questioning my sanity, until I found this..
    
    
    import algorithm
    
    echo binarySearch([8, 2, 5, 4], 5)                 #  2
    echo binarySearch([8, 2, 5, 4, 7], 5)              #  2
    echo binarySearch([8, 2, 5, 4, 7, 0], 5)           # -1
    echo binarySearch([8, 2, 5, 4, 7, 0, 1], 5)        # -1
    echo binarySearch([8, 2, 5, 4, 7, 0, 1, 6], 5)     #  2
    echo binarySearch([8, 2, 5, 4, 7, 0, 1, 6, 3], 5)  #  2
    
    
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