Tested against crosstool-NG version 1.25.0. Follow the instructions below to install it and then execute ct-ng build in this directory.
git clone --depth 1 --branch crosstool-ng-1.25.0 --single-branch https://github.com/crosstool-ng/crosstool-ng.git
cd crosstool-ng
sudo apt install \
autoconf autoconf-archive \
autopoint \
bison \
build-essential \
cmake \
flex \
gawk \
gettext \
gtk-doc-tools \
help2man \
libbz2-1.0 libbz2-dev \
libffi8 libffi-dev \
libgdbm-compat4 libgdbm-compat-dev \
libgdbm6 libgdbm-dev \
liblzma5 liblzma-dev \
libncurses-dev \
libnsl2 libnsl-dev \
libreadline8 libreadline-dev \
libssl-dev \
libtirpc3 libtirpc-dev \
libtool-bin \
libuuid1 uuid-dev \
patchelf \
pkg-config \
python3-tk \
texinfo \
xsltproc \
yacc \
zlib1g zlib1g-dev
./bootstrap
./configure --prefix=$HOME/.local
make -j11
make install