zstd files/0 -D dicts/0 -q
zstd -t files/0.zst -D dicts/0
files/0.zst         : 1000 bytes 
zstd -t files/0.zst -D dicts/1 && die "Must fail" ||:
files/0.zst : Decoding error (36) : Dictionary mismatch 
zstd -t files/0.zst            && die "Must fail" ||:
files/0.zst : Decoding error (36) : Dictionary mismatch