lfs-book-zh_CN/chapter05/installasroot.xml

<sect1 id="ch05-installasroot">
<title>Install all software as user root</title>

<para>
It's best if you login as root or su to root when installing these
files. That way you are assured that all files are owned by user root,
group root (and not owned by the userid of your non-root user) and if a
package wants to set special permissions it can do so without problems
due to non-root access.
</para>

<para>
If you read the documentation that comes with Glibc, Gcc and other
packages they recommend not to compile the packages as user root. We
feel it's safe to ignore that recommendation and compile as user root
anyways. Hundreds of people using LFS have done so without any problems
whatsoever and we haven't encountered any bugs in the compile processes
that cause harm. So it's pretty safe (never can be 100% safe though, so
it's up to you what you end up doing).
</para>

</sect1>