Thanks Taavi and Ahmad for your tips! Unfortunately none of the `debian/rules` tricks worked, see what I tried and notes in commit 77a3d40c at https://salsa.debian.org/go-team/packages/usql/-/merge_requests/1/commits
Eventually, the only thing that worked was adding `//go:build ignore` lines in specific files instead. There is still a bunch of dependency issues to solve, though. Currently I am trying to debug why it fails to load Chroma despite it being a dependency.. ± grep chroma debian/control golang-github-alecthomas-chroma-dev, ± dpkg-buildpackage ... src/github.com/xo/usql/drivers/drivers.go:17:2: cannot find package "github.com/alecthomas/chroma/v2" in any of: /usr/lib/go-1.24/src/github.com/alecthomas/chroma/v2 (from $GOROOT) /tmp/build/source/debian/.build/upstream/src/github.com/alecthomas/chroma/v2 (from $GOPATH) src/github.com/xo/usql/drivers/drivers.go:18:2: cannot find package "github.com/alecthomas/chroma/v2/lexers" in any of: /usr/lib/go-1.24/src/github.com/alecthomas/chroma/v2/lexers (from $GOROOT) /tmp/build/source/debian/.build/upstream/src/github.com/alecthomas/chroma/v2/lexers (from $GOPATH)