Re: configure: error: C preprocessor "/lib/cpp" fails sanity check

[Eric Blake]

On 11/16/18 5:30 PM, Fabiano Sidler wrote:
> Hi folks!
>
> When trying to configure (binutils and gmp, in that case), I'm getting this:
> === snip ===
> checking how to run the C preprocessor... /lib/cpp
> configure: error: in `/home/luser/Downloads/binutils-2.26.1/libiberty':
> configure: error: C preprocessor "/lib/cpp" fails sanity check
> See `config.log' for more details.
> make[1]: *** [Makefile:7985: configure-libiberty] Error 1
> make[1]: Leaving directory '/home/luser/Downloads/binutils-2.26.1'
> make: *** [Makefile:846: all] Error 2
> === snap ===

Are you attaching the same config.log? If so, something is indeed odd, 
because looking at your attachment:

> config.log
>
> This file contains any messages produced by compilers while
> running configure, to aid debugging if configure makes a mistake.
>
> It was created by configure, which was
> generated by GNU Autoconf 2.64.  Invocation command line was
>
>    $ ./configure
>
> ## --------- ##
> ## Platform. ##
> ## --------- ##
>
> hostname = elux-devel
> uname -m = x86_64
> uname -r = 4.14.39
> uname -s = Linux
> uname -v = #1 SMP Fri Jul 20 13:35:34 CEST 2018

Okay, you've told us your kernel,...

> configure:4111: checking for gcc
> configure:4127: found /usr/local/bin/gcc
> configure:4138: result: gcc
> configure:4367: checking for C compiler version
> configure:4376: gcc --version >&5
> gcc (GCC) 5.4.0

and it looks like you are using a self-built gcc,

> configure:14766: checking whether to enable maintainer-specific portions of 
> Makefiles
> configure:14775: result: no
> configure:15032: creating ./config.status
>
> ## ---------------------- ##
> ## Running config.status. ##
> ## ---------------------- ##
...

> configure: exit 0

but this config.log says that configure ran to completion, without any 
warning about /lib/cpp failing a sanity check, which makes it hard to 
see the "more details" that stdout/stderr said we should be looking for 
in evidence why configure failed.

--
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3266
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