Hi Chris,
I wrote earlier:
> My first guess is that '/gnu/store/…-linux-next-…-checkout/include'
> should not be in the C include path while compiling that file, but that
> it's getting added. The difference might be due to the fact that the
> 'source' in this case is a directory instead of a tarball.
I see now what's happening more precisely. Our gcc-7 package inherits
from gcc-6 'native-search-paths' for the CPATH variable. Because of
this, the 'set-paths' phase in 'gnu-build-system' sets the CPATH to
include <NATIVE_INPUT>/include for all native inputs that are
directories with an 'include' subdirectory.
The 'source' is itself a native input. When it's a tarball, it will not
be included, but when it's a source checkout, it _is_ included, although
it shouldn't be.
> For now, I would try packing the git checkout as a tarball, and then
> using that tarball as your 'source'.
I'm now fairly confident that this workaround would work. Another
workaround would be to add another phase that removes the CPATH
component corresponding to 'source', as Tobias does.
Mark
