Numbers aren't adding up

[skull-squadron]

du output

192M	/opt/rh/gcc-toolset-12/root
192M	/opt/rh/gcc-toolset-12
192M	/opt/rh
36M	/opt/gitlab/git/bin
59M	/opt/gitlab/git/libexec
72K	/opt/gitlab/git/share
95M	/opt/gitlab/git 
267M	/opt/gitlab/go/1.20.4
267M	/opt/gitlab/go
636M	/opt/gitlab/rust/cargo
1.2G	/opt/gitlab/rust/rustup
1.8G	/opt/gitlab/rust
2.2G	/opt/gitlab
2.4G	/opt

git/ isn't 2.3G. du says 95M but it's ~25 M because 4 files are hardlinked to each other.