Allow cc_toolchain injection for cuda_toolchain

[hofbi]

Here in the cuda_toolchain rule, you specify the "_cc_toolchain": attr.label(default = "@bazel_tools//tools/cpp:current_cc_toolchain"). I would like to specify a different cc toolchain. What I am currently at is

cuda_toolchain(
    name = "nvcc-local",
    compiler_executable = "path to my nvcc compiler",
    toolchain_config = ":my-nvcc-config",
    _cc_toolchian = ":my-cc-toolchain"  # <-- this one fails
)

Any idea what's wrong with my setup?

[cloudhan]

What is the error message?

[hofbi]

no such attribute '_cc_toolchain' in 'cuda_toolchain' rule (did you mean '$cc_toolchain'?)

[cloudhan]

https://bazel.build/extending/rules#private_attributes_and_implicit_dependencies

[cloudhan]

To allow some kind of customizaiton, we might instead of implement something like

https://github.com/bazelbuild/rules_python/blob/612baef1f14d1af89594f45559bc9c11a50d390a/python/BUILD.bazel#L340-L342

depends on something like current_cuda_cc_toolchain.

[cloudhan]

Related to #194

[hofbi]

Thanks, closing this as duplicate of #194