bug#30756: GCC >= 6 '-isystem' and C_INCLUDE_PATH behavior changed, breaking

[Ludovic Courtès]

Hello,

Maxim Cournoyer <address@hidden> skribis:

> Thank you for working on a fix, and properly understanding the root
> cause of the problem.  I've reviewed it and it seems great!  I see that
> it is already in core-updates.  I will go ahead and proceed with
> rebuilding the world and see what ensues! :-)

Thank you!  Let me know if anything doesn’t work as advertised!

Ludo’.