make: build for Cortex fails due to '-W missining-include-dirs` #9452
Description
Description
Sadly, this is the second time in a week I have to open this issue. I can, again, not build anything for Cortex-M boards due to the -Werror=missing-include-dirs. This time though the compiler complains that some actually existing include path(s) can not be found.
Example building hello-world for the samr21-xpro:
Building application "hello-world" for "samr21-xpro" with MCU "samd21".
cc1: error: -I/home/hauke/dev/riot/RIOT/core/include: No such file or directory [-Werror=missing-include-dirs]
cc1: all warnings being treated as errors
/home/hauke/dev/riot/RIOT/Makefile.base:83: recipe for target '/home/hauke/dev/riot/RIOT/examples/hello-world/bin/samr21-xpro/application_hello-world/main.o' failed
make[1]: *** [/home/hauke/dev/riot/RIOT/examples/hello-world/bin/samr21-xpro/application_hello-world/main.o] Error 1
/home/hauke/dev/riot/RIOT/examples/hello-world/../../Makefile.include:359: recipe for target '/home/hauke/dev/riot/RIOT/examples/hello-world/bin/samr21-xpro/application_hello-world.a' failed
make: *** [/home/hauke/dev/riot/RIOT/examples/hello-world/bin/samr21-xpro/application_hello-world.a] Error 2
The location of -I/home/hauke/dev/riot/RIOT/core/include is actually correct, so I don't quite get the why the compiler is angry here...
Anyone with similar issues or an idea how to fix this?