Weird dependency on ncurses

[Kozzi11]

I have tried ldc2-1.1.0-beta3-linux-armv7hf.tar.xz but it does not work because of this error:

error while loading shared libraries: libncurses.so.5: cannot open shared object file: No such file or directory

I know what that mean, but I do not know why ldc need ncurses?

[dnadlinger]

It's probably pulled in by LLVM (as in, some LLVM support library depends on ncurses, and then the ldflags we get from llvm-config contain it). Not too sure what we can do about this, other than getting upstream LLVM to fix that.

You can check whether it indeed comes from there by manually running llvm-config. Maybe we are passing too many components to llvm-config?

[dnadlinger]

We could also consider filtering out anything ncurses-related from the llvm-config output, but that would be quite hacky.

[kinke]

This is a purely optional dependency of LLVM (nowadays on libtinfo). If the library is found on the system building LLVM, LLVM includes it, and we'll drag the dependency in when linking LDC, as David mentioned.

This now also makes the v1.15.0-beta1 Linux x86_64 binary (built on Ubuntu 16.04) produce this on Ubuntu 14.04 (Travis):

/home/travis/dlang/ldc-1.15.0-beta1/bin/ldc2: /lib/x86_64-linux-gnu/libtinfo.so.5: no version information available (required by /home/travis/dlang/ldc-1.15.0-beta1/bin/ldc2)

=> LDC-LLVM 8.0.0 will use -DLLVM_ENABLE_TERMINFO=OFF -DLLVM_ENABLE_LIBEDIT=OFF in the CMake command line.