A var missing from fsdb2vcd output doesn't prove it's missing from the FSDB

When you use fsdb2vcd as a black-box content check, remember that VCD has no type for some SystemVerilog types. The fsdb2vcd type list in the Verdi Command Reference has no string type, so a string variable missing from the VCD tells you nothing about whether the FSDB recorded it. Check the documented supported-type list first, and use another documented reader (for example fsdbreport -s on the signal, with a known signal as a control) before you label a class 'not dumped'. Real values have a similar problem: the VCD text had at most 16 significant digits, so it can't be used for bit-exact binary64 comparison.