I cannot reproduce it in my lab, but there are some precarious places in Makefiles for Zabbix Agent 2. You define GOOS and GOARCH vars with next expressions:
GOOS = `go env GOOS`
GOARCH = `go env GOARCH`
But `bla bla bla` syntax is deprecated, so in my environment build fails with error
cmd/go: unsupported GOOS/GOARCH pair `go env GOOS`/`go env GOARCH` thougth vars are defined to "linux" and "amd64" respectively and go env show them.
But, if I change definitions to $() syntax like:
GOOS = $(go env GOOS)
GOARCH = $(go env GOARCH)
All works as expected. Maybe it's my environment issue, but I guess you better use modern syntax.