error: 'FALLOC_FL_COLLAPSE_RANGE' was not declared in this scope about hydra HOT 5 CLOSED

That seems to be an issue with the older versions of clang, being not aware of the recent fs flags such as FALLOC_FL_COLLAPSE_RANGE.
Instead of using the system's clang, could you retry building hydra with the llvm included in the repo?

from hydra.

Should I build the llvm in the directory llvm-build? But I cannot make install directly, what should I do...?

from hydra.

As per the error message, cmake 2.8.12 is too old (was released in 2013) to compile llvm toolchain that we utilize. I would suggest you to install a newer version of cmake (3.4.3 or higher) in your system. If you are running ubuntu 16.04 or higher, running apt update && sudo apt upgrade will suffice.

from hydra.

Holy God, plz help me! It turns out no use for some errors.
As you can see, I have compiled and installed the cmake and clang completely:


And I have make install in the llvm-build directory successfully:

But when I tried to sudo make build-ext4-imgwrp, it's still failed:

What's the problem in here? It's too hard for me...

from hydra.

I wonder if the proper cmake arguments were set when your were manually building llvm.
As the Makefile handles everything, would you try cloning hydra repository again, and building from scratch?

from hydra.