Software or hardware issue?

hi,
I am trying to build the px4-v2 target and it shows the firmware ‘ArduCopter-v2.px4’ has already been built except for some so-called ‘fatal’ problems
fatal: Not a git repository: d:/px4/v321/ardupilot/modules/…/…/.git/modules/modules/PX4Firmware
fatal: Not a git repository: d:/px4/v321/ardupilot/modules/PX4NuttX/nuttx//…/…/.git/modules/modules/PX4NuttX
Failed to get px4 hash
Failed to get nuttx hash

I search the web and some people say it could be totally ignored, then I ignored the problem and uploaded the firm to my pixhawk, and connected it to the Mission Planner, it seems the software works, but the software exhibits “Bad Gyro Health” and sometimes ‘Error Compass variance’, what these messages mean? is it the problem of hardware or a problem of the firmware I built?

Thank you and hope someone can help!

is there anyone can answer my question?