vet error: set declared but not used

[eclipseo]

Go 1.12.2, on Fedora Rawhide, x86_64, opengcs v0.3.9:

Testing    in: /builddir/build/BUILD/opengcs-0.3.9/_build/src
         PATH: /builddir/build/BUILD/opengcs-0.3.9/_build/bin:/builddir/.local/bin:/builddir/bin:/usr/bin:/bin:/usr/sbin:/sbin:/usr/local/sbin
       GOPATH: /builddir/build/BUILD/opengcs-0.3.9/_build:/usr/share/gocode
  GO111MODULE: off
      command: go test -buildmode pie -compiler gc -ldflags "-X github.com/Microsoft/opengcs/version=0.3.9 -extldflags '-Wl,-z,relro -Wl,--as-needed  -Wl,-z,now -specs=/usr/lib/rpm/redhat/redhat-hardened-ld '"
      testing: github.com/Microsoft/opengcs
github.com/Microsoft/opengcs/service/gcs/bridge
# github.com/Microsoft/opengcs/service/gcs/bridge
vet: ./bridge_unit_test.go:149:6: set declared but not used
FAIL	github.com/Microsoft/opengcs/service/gcs/bridge [build failed]

[eclipseo]

Testing    in: /builddir/build/BUILD/opengcs-0.3.9/_build/src
         PATH: /builddir/build/BUILD/opengcs-0.3.9/_build/bin:/builddir/.local/bin:/builddir/bin:/usr/bin:/bin:/usr/sbin:/sbin:/usr/local/sbin
       GOPATH: /builddir/build/BUILD/opengcs-0.3.9/_build:/usr/share/gocode
  GO111MODULE: off
      command: go test -buildmode pie -compiler gc -ldflags "-X github.com/Microsoft/opengcs/version=0.3.9 -extldflags '-Wl,-z,relro -Wl,--as-needed  -Wl,-z,now -specs=/usr/lib/rpm/redhat/redhat-hardened-ld '"
      testing: github.com/Microsoft/opengcs
github.com/Microsoft/opengcs/service/gcs/core/gcs
# github.com/Microsoft/opengcs/service/gcs/core/gcs
vet: ./gcs_test.go:754:6: pid declared but not used
FAIL	github.com/Microsoft/opengcs/service/gcs/core/gcs [build failed]