Clang17.0 can not find headers after building from source and installing it on macOS 10.15

Beginners
1

I am on macOS 10.15
I compiled clang using Apple-Clang 12
I enabled the Release BUILD, and I selected projects “clang; lldb; lld”
I also changed via ccmake the configuration to build lldb framework and turned off the Tests.
Finally I changed the CMAKE_INSTALL_PREFIX because I did not want to override the apple-clang installation.

and then run cmake --build build --target install
followed by (6 hours later)
cd build && ninja install.

however, clang did not install the headers, when trying to include anything from the standard library headers, it can not find them, further more I checked that the directory:

bin/clang++…/include/c++/v1 does not exist.
It was not installed,
any ideas on what might caused clang installation to miss the headers?

2

here is an example of the output

3

You did not add libcxx to the enabled project. Thus it was not built.
See bootstrapping:
https://libcxx.llvm.org/BuildingLibcxx.html#bootstrapping-build

4

Will give it a try now, thanks!

5

This worked for the header problem, I encountered another one, which it was complaining about non-standard headers, like pthreads and the like.

I installed Xcode command line tools, and I exported the SDKROOT env variable to be
the same as:
xcrun --show-sdk-path --sdk macosx

not sure if that was the correct way, but it did solve it for now.