Minimization fails for one example

I have added the file examples/tbeg-dist-paper. While refine works for this input file, minimize fails:

$ copar minimize examples/tbeg-dist-paper 
copar: ./Data/Vector/Generic.hs:248 ((!)): index out of bounds (1,1)
CallStack (from HasCallStack):
  error, called at ./Data/Vector/Internal/Check.hs:87:5 in vector-0.12.1.2-3ubVJHVYUZgKP2BOIpfTrf:Data.Vector.Internal.Check

$ copar refine tbeg-dist-paper
Block 0: s5
Block 1: s4
Block 2: s3
Block 3: s1
Block 4: s2

(This is also the reason why the CI for master fails at the moment; I simply added the example file because I didn't expect anything bad can happen...)