When using the recommended CC=/usr/local/libexec/ccache/world/cc, the logic
here was considering ccache to be an external compiler and skipping building
the internal compiler. This leads to problems where the internal compiler
has flags that the source files depend on that the host compiler does not
This is currently relevant building 10+ on a host that is <10
using ccache as the build tries to use the host /usr/bin/cc (gcc) with clang
flags such as -Qunused-arguments.
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