gllvm: FreeBSD: Error reading the .llvm_bc section of ELF file

I’m using gllvm to compile FreeBSD libc and libc++ into LLVM bitcode.

When running get-bc on resulting shared libraries, I get:

Error reading the .llvm_bc section of ELF file

Extracting from .a library partially works - some .o files gets extracted, but others fail with the same error.

Is there any debugging switch in gllvm or maybe any other idea how to fix that?