New comment by zdtcd on void-packages repository

https://github.com/void-linux/void-packages/pull/15688#issuecomment-545020837

Comment:
I think we have a bug with xbps/build system, I used to have this problem when packaging firefox some times ago.

WRT this PR, I tried to run
```
./xbps-src pkg oblibs
./xbps-src chroot
```

The file `/usr/include/pwd.h` is really missed.