Instructions on the px4 build do not seems to work

I tried the instruction on the px4 developer pages. They didn’t work.
1st I had to manually update the python setup tools and yaml.
Then when I finally got to building the firmware, it fails to start

Total time: 2 seconds
Options parsed, starting Sim.
Starting GUI...
3D [dev] 1.6.0-pre12-daily-experimental daily

WARNING: An illegal reflective access operation has occurred
WARNING: Illegal reflective access by (rsrc:j3dcore.jar) to method    sun.awt.AppContext.getAppContext()
WARNING: Please consider reporting this to the maintainers of
WARNING: Use --illegal-access=warn to enable warnings of further illegal reflective access operations
WARNING: All illegal access operations will be denied in a future release
Inconsistency detected by dl-lookup.c: 111: check_match: Assertion `version->filename == NULL || ! _dl_name_match_p (version->filename, map)' failed!

How to I fix this ?

The same happened to me, does anyone know how to fix it???