[llvm] fix debug build

[abique]

LLVM did no build in debug because the include directory was removed.
I'm not sure this behavior is correct (llvm port). Yet I did add the policy so it builds.

[PhoebeHui]

@abique, could you report an issue for this? I'm unsure what failures that you encountered.

[abique]

@PhoebeHui the build failed because the include directory was empty.

[abique]

This allows the debug build to complete with an empty include folder.

[yurybura]

@PhoebeHui the build failed because the include directory war empty.

Hello @abique, could you tell which directory is empty? Could you provide also install command to reproduce your issue?
All known empty directories should be removed. You can find the following code:

vcpkg/ports/llvm/portfile.cmake

Lines 199 to 203 in eb1dac2

	# Remove empty include directory include/clang-tidy/plugin
	file(GLOB_RECURSE INCLUDE_CLANG_TIDY_PLUGIN_FILES "${CURRENT_PACKAGES_DIR}/include/clang-tidy/plugin/*")
	if(NOT INCLUDE_CLANG_TIDY_PLUGIN_FILES)
	file(REMOVE_RECURSE "${CURRENT_PACKAGES_DIR}/include/clang-tidy/plugin")
	endif()

vcpkg/ports/llvm/portfile.cmake

Lines 209 to 213 in eb1dac2

	# Remove empty include directory /include/flang/Config
	file(GLOB_RECURSE INCLUDE_FLANG_CONFIG_FILES "${CURRENT_PACKAGES_DIR}/include/flang/Config/*")
	if(NOT INCLUDE_FLANG_CONFIG_FILES)
	file(REMOVE_RECURSE "${CURRENT_PACKAGES_DIR}/include/flang/Config")
	endif()

[abique]

Build in debug, see the portfile it is doing:
file(REMOVE_RECURSE ${CURRENT_PACKAGES_DIR}/debug/include)

[PhoebeHui]

@abique, Removing debug/include folder is by design in vcpkg, it will check the folder in post-build validation step. When you use the port, it will use the headers from include folder.

Include files should not be duplicated into the /debug/include directory. If this cannot be disabled in the project cmake, use
    file(REMOVE_RECURSE ${CURRENT_PACKAGES_DIR}/debug/include)

[abique]

In my case I did build the debug with a custom toolchain/triplet with only debug.

[abique]

Could it be that it is a vcpkg error instead?
The scenario to reproduce it would be to install a library in debug without the release version.

[PhoebeHui]

@abique, this is a known common issue in vcpkg see #6045.

I would suggest to use overlay or custom ports instead.

[abique]

Is it unsupported to install only the debug version of a port?

[PhoebeHui]

@abique, only install debug or release version of a port may all have issues, or not, it depends what the port that was used. We hope this issue would be solved in future, however, currently we would suggest to solve this issue by using overlay or custom ports.

[abique]

I understand.
I close this issue.
Thank you :)