Support to just log the wave file, not open GUI

[PelleEikeberg]

As the title states, I would like there to be an option to just log the wave file. When I run N-number of tests, I would like to save the waves as I might want to open the one(s) that fail/have issues. Right now, I have a solution which involves setting a pre_config which manually sets the "--wave=" flag for NVC (--wave/--vcd/--fst for GHDL) using the output_path, but it would be nice for there to be an option: --log_wave/-logw when using NVC/GHDL which would place the wave.* file in the NVC/GHDL folder in each test case.

[tasgomes]

@PelleEikeberg

For GHDL this seems to be supported already on VUnit v5.0.0.dev10. I passed the arguments --viewer-fmt vcd to run.py and got a VCD file on each test case output folder, without running in GUI mode. This also works using --viewer-fmt fst.

I believe this does not work yet the same way for NVC but there are efforts towards that: #1101

[PelleEikeberg]

Okay, I will close this issue then. For some reason, "--viewer-fmt vcd" runs into an error on my run.py, but I got it working trying to make a minimal example, so it's my setup. I will let the NVC pre_config be since it does not work per now, but yes, a --wave ption would be super!