The ubuntu snap version doesn't have the latest lensfun data files. For reasons, it seems to have hard coded the lensfun data files, and also for reasons, the snap seems to be mounted as read-only file system, so you can't just copy the lensfun files there.
lensfun needs to be updated using lensfun-update-data. If you type it in cli it would suggest what pkg to install to get it on ubuntu.
trying to compile darktable myself. checking out the source turns out to take forever.
deb
sed -e '/^#\sdeb-src /s/^# *//;t;d' "/etc/apt/sources.list" \
| sudo tee /etc/apt/sources.list.d/darktable-sources-tmp.list > /dev/null \
&& (
sudo apt-get update
sudo apt-get build-dep darktable
)
sudo rm /etc/apt/sources.list.d/darktable-sources-tmp.list
git
git clone --recurse-submodules --shallow-submodules -- --depth 1 https://github.com/darktable-org/darktable.git
cd darktable
git fetch --tags
git checkout tags/release-4.2.1
build
./build.sh --prefix /opt/darktable-test --build-type Release
install (above cmd would tell you what to do once it's done), note the sudo -E, you need that to make jsonschema python pkg visible
sudo -E cmake --build "/home/wei/darktable/darktable/build" --target install -- -j16