Building Pulsar for Conan works with protobuf 3.12.4 which isn't supported remote version. For this to work you need to first clone conan-center-index and build protobuf 3.12.4
conan profile detect
git clone [email protected]:conan-io/conan-center-index.git
cd conan-center-index
git apply conan-center-index.patch
conan create recipes/protobuf/all --version 3.12.4 --build=missing
cd ../pulsar_build
conan create . --build=missing