ERROR: Current execution environment is VCO=aoi. Software tree is for environment VCO=ixl

I updated Calibre into order to try to address a warning, and I ended up making a mess. The new error was:

ERROR: Current execution environment is VCO=aoi. Software tree is for environment VCO=ixl

Deep down in the bowels of Calibre I found an environmental variable that I could set to change behavior. We'll see how it works:

export USE_CALIBRE_VCO=ixl

No errors of doom so far, but that doesn't mean that it will work.