Details on this package are located in Section 8.14.2, “Contents of M4.”
The M4 package contains a macro processor.
First, make some fixes introduced by glibc-2.43:
sed -r '/_GL_EXTERN_C/s/w?memchr|bsearch/(&)/' \
-i $(find -name \*.in.h)
Prepare M4 for compilation:
./configure --prefix=/usr \
--host=$LFS_TGT \
--build=$(build-aux/config.guess)
Compile the package:
make
Install the package:
make DESTDIR=$LFS install
Details on this package are located in Section 8.14.2, “Contents of M4.”