lfs-book-zh_CN/chapter05/diffutils-exp.xml

<sect2>
<title>Command explanations</title>

<para>
<userinput>CPPFLAGS=-Dre_max_failures=re_max_failures2:</userinput> The
CPPFLAGS variable is a variable that's read by the cpp program (C 
PreProcessor). The value of this variable tells the preprocessor to 
replace every instance of re_max_failures it finds by re_max_failures2 
before handing the source file to the compiler itself for compilation. This 
package has problems linking statically on certain platforms (depending 
on the Glibc version used on that system) and this construction fixes
that problem.
</para>

</sect2>