Here is the repo:

https://git.devuan.org/Daemonratte/gtk2-ng

I added the two patches that the AUR maintainers apply to gtk2, implemented stefan11111's g_qsort_with_data to g_sort_array modernisation and fixed all the compiler warnings so you can compile it on a modern system.

Tested both gcc 14 and clang 21 (and leafpad)

Future plans:
Backport further improvements by stefan11111's (a famous Xlibre contributer)
Backport new features from Ardour's gtk2 fork ytk (without breaking ABI
Getting rid of errors and bugs
Test compiling with gcc 15
Find another name?
Change the license to gpl3 if possible (probably not)

Please test it and report any errors to me

Edit:
Here are build instructions (for installing it on the system:

touch README
autoreconf -fvi
./configure --prefix=/usr --sysconfdir=/etc --localstatedir=/var --with-xinput=yes
make -j"$(nproc)"
sudo make install

if you only want to test it, only use

./configure --prefix=/TESTDIR --with-xinput=yes
make -j"$(nproc)"
make install

and change TESTDIR to another location