testfw: support immediate test output to console
There is VUnit --verbose
flag, but the output still goes to file and GHDL has set block flushing, not line flushing.
Options:
- Do not capture output to file
- Force GHDL to use line buffering
- Output to PTY, connected to file
- LD_PRELOAD with patched fopen (but first check that ADA uses libc's file functions)
- Force GHDL to periodically flush the file
- via gdb, /proc/*/fds, fflush (assuming libc api)
- too bothersome, cannot gdb in docker