1) clone git
2) pip installed setuptools_rust and setuptools_gettext
3) make
Copying rust artifact from target/debug/brz to brz
building 'breezy.bzr._static_tuple_c' extension
x86_64-linux-gnu-gcc -Wno-unused-result -Wsign-compare -DNDEBUG -g -fwrapv -O2 -Wall -g -fstack-protector-strong -Wformat -Werror=format-security -g -fwrapv -O2 -fPIC -I/usr/include/python3.9 -c breezy/bzr/_static_tuple_c.c -o build/temp.linux-x86_64-cpython-39/breezy/bzr/_static_tuple_c.o
breezy/bzr/_static_tuple_c.c:29:10: fatal error: _simple_set_pyx_api.h: No such file or directory
29 | #include "_simple_set_pyx_api.h"
| ^~~~~~~~~~~~~~~~~~~~~~~
compilation terminated.
error: command '/usr/bin/x86_64-linux-gnu-gcc' failed with exit code 1
make: *** [Makefile:41: extensions] Error 1
figured it out - was missing cython3 package. Something in the build order has changed and the logic in setup.py to give a clean error in this situation is getting bypassed.