Message5515

So upgrading glibc seems to have big consequences for the stability of the system if I have to believe the warning message that their 'configure' throws:

*** On GNU/Linux systems the GNU C Library should not be installed into
*** /usr/local since this might make your system totally unusable.
*** We strongly advise to use a different prefix.  For details read the FAQ.
*** If you really mean to do this, run configure again using the extra
*** parameter `--disable-sanity-checks'.

Their FAQ contradicts this though, saying '/usr/local/' is safe:

"Like all other GNU packages GNU libc is designed to use a base
directory and install all files relative to this.  The default is
/usr/local, because this is safe (it will not damage the system if installed
there).  If you wish to install GNU libc as the primary C library on your
system, set the base directory to /usr (i.e. run configure --prefix=/usr
<other_options>).  Note that this can damage your system; see question 2.3 for
details."

So this is confusing, sigh... suggestions?