Building binutils fails with "error: package binutils-doc not in control info"

Hi, I am trying to build binutils using your scripts for x86_64-linux-gnu triplet. Specifically, I checked out `applied/2.38-4ubuntu2.1` tag on Ubuntu 20.04.

From reading debian/README files I got following commands:
```bash
rm -f stamps/control
debian/rules stamps/control TARGET=amd64
BACKPORT=1 DEB_BUILD_OPTIONS="nocross nohppa64 nostrip" TARGET=amd64 dpkg-buildpackage -j8 -b -uc -us -d
```
(BACKPORT option is my attempt to solve things, removing it does not change result)
This snippet fails with following error:
```
...
d_src=debian/binutils-x86-64-linux-gnu/usr/x86_64-linux-gnu/x86_64-linux-gnu/lib; \
d_dst=debian/binutils-x86-64-linux-gnu/usr/lib/x86_64-linux-gnu; \
for lib in libbfd libopcodes; do \
  so=$(basename $(echo $d_src/$lib*amd64*.so)); \
  mv $d_src/$so $d_dst/.; \
  ln -sf ../../../lib/x86_64-linux-gnu/$so $d_src/$lib.so; \
  mv $d_src/$lib.a $d_dst/${lib}-2.38-amd64.a; \
  ln -sf ../../../lib/x86_64-linux-gnu/$lib-2.38-amd64.a $d_src/$lib.a; \
done
mv: cannot stat 'debian/binutils-x86-64-linux-gnu/usr/x86_64-linux-gnu/x86_64-linux-gnu/lib/libbfd*amd64*.so': No such file or directory
make: *** [debian/rules:868: stamps/install.amd64] Error 1
dpkg-buildpackage: error: debian/rules binary subprocess returned exit status 2
```
Changing TARGET to x86_64-linux-gnu does not help.

Not passing TARGET seems to work longer, `binutils-for-host` package is successfully created but after this build fails with
```
dpkg-gencontrol -Pdebian/binutils-doc -pbinutils-doc
dpkg-gencontrol: error: package binutils-doc not in control info
make: *** [debian/rules:1373: binary-indep] Error 255
dpkg-buildpackage: error: debian/rules binary subprocess returned exit status 2
```
`binutils-doc` is not in debian/control indeed and I can't understand how to get it there properly.

How to resolve these problems, what am I doing wrong?