github.com/jimmyx0x/go-ethereum@v1.10.28/cmd/evm/testdata/4/readme.md (about)

     1  These files examplify a transition where a transaction (excuted on block 5) requests
     2  the blockhash for block `4`, but where the hash for that block is missing. 
     3  It's expected that executing these should cause `exit` with errorcode `4`.