Re: [PATCH] gnu: cross-gcc-arguments: Disable libitm, libvtv and, libsanitizer.

[Ricardo Wurmus <ricardo.wurmus@mdc-berlin.de>]

Manolis Ragkousis <manolis837@gmail.com> writes:

> This is a follow up to better explain what the problem is with the
> sans-libc cross gcc in the (gnu packages cross-base) module.
>
> In the latest master if you try to build gcc-cross-sans-libc with:
>
> ./pre-inst-env guix build -e '((@@(gnu packages cross-base) cross-gcc)
> "i686-linux-gnu")' -c8
>
> gcc modules libitm, libvtv and libsanitizer fail to build with
> "configure: error: C compiler cannot create executables".
>
> This happens because there is no libc present at that point and the
> problem was introduced with commit ca7ef4d41854218c which enabled c++.

I find this very odd.  I’m the author of that commit and I did this to
be able to build a C and C++ cross compiler for arm-none-eabi (which I
still haven’t submitted to the ML).  At no point did I see any errors
about libitm, libvtv, or libsanitizer.

My cross-compiler is made with little more than “(cross-gcc
"arm-none-eabi")”, so I wonder why you’d have problems with building a
cross-compiler for “i686-linux-gnu”.

> At that stage no linking can happen so the best solution is to just
> disable the modules. It does not affect anything after that.

I cannot verify this as I’m not familiar with all this (and I cannot
rebuild my cross-compiler at this point).  This doesn’t mean I object to
this change, I just don’t understand why we see it with “i686-linux-gnu”
but not with my “arm-none-eabi” build :-/

Could you please also add some comment above the new flags to concisely
say why they are needed?  That’s just to prevent people like me from
removing the flags in the future because “they don’t seem to do
anything” :)

Thanks!

~~ Ricardo