This "-D__nonnull\\(params\\)=" leads to a compilation failure in e.g.
the configure phase:
configure:21131: gcc -c -D__nonnull\(params\)= conftest.c >&5
<command-line>: warning: ISO C99 requires whitespace after the macro name
<command-line>: error: stray '\' in program
<command-line>: error: expected ',' or ';' before '(' token
<command-line>: error: stray '\' in program
According to the commit this isn't even needed on Linux.
I confirmed that this is an (expectable) glibc-2.34 thing by checking
that
* the issue doesn't occur with gcc 10/11 on a recent glibc-2.33 staging.
* the issue DOES occur in a docker container with Fedora rawhide (which
has glibc 2.34 and gcc 11).
49028fb110