Test failure: cannot use tracer (type *TestTracer) as type Tracer in argument to Trace

[eclipseo]

Go 1.12.5, on Fedora Rawhide x86_64, latest master:

Testing    in: /builddir/build/BUILD/go-bcd-5d8e01b2f0438922289238fd3ba043761daf1102/_build/src
         PATH: /builddir/build/BUILD/go-bcd-5d8e01b2f0438922289238fd3ba043761daf1102/_build/bin:/builddir/.local/bin:/builddir/bin:/usr/bin:/bin:/usr/sbin:/sbin:/usr/local/sbin
       GOPATH: /builddir/build/BUILD/go-bcd-5d8e01b2f0438922289238fd3ba043761daf1102/_build:/usr/share/gocode
  GO111MODULE: off
      command: go test -buildmode pie -compiler gc -ldflags "-X github.com/backtrace-labs/go-bcd/version.commit=5d8e01b2f0438922289238fd3ba043761daf1102 -X github.com/backtrace-labs/go-bcd/version=0 -extldflags '-Wl,-z,relro -Wl,--as-needed  -Wl,-z,now -specs=/usr/lib/rpm/redhat/redhat-hardened-ld '"
      testing: github.com/backtrace-labs/go-bcd
github.com/backtrace-labs/go-bcd
# github.com/backtrace-labs/go-bcd [github.com/backtrace-labs/go-bcd.test]
./bcd_test.go:119:13: cannot use tracer (type *TestTracer) as type Tracer in argument to Trace:
	*TestTracer does not implement Tracer (missing AddCallerGo method)
./bcd_test.go:143:19: cannot use tracer (type *TestTracer) as type Tracer in argument to Trace:
	*TestTracer does not implement Tracer (missing AddCallerGo method)
./bcd_test.go:152:18: cannot use tracer (type *TestTracer) as type Tracer in argument to Trace:
	*TestTracer does not implement Tracer (missing AddCallerGo method)
./bcd_test.go:160:18: cannot use tracer (type *TestTracer) as type Tracer in argument to Trace:
	*TestTracer does not implement Tracer (missing AddCallerGo method)
./bcd_test.go:174:20: cannot use &tracer (type *TestTracer) as type Tracer in argument to Trace:
	*TestTracer does not implement Tracer (missing AddCallerGo method)
./bcd_test.go:211:15: cannot use t (type *TestTracer) as type Tracer in argument to Recover:
	*TestTracer does not implement Tracer (missing AddCallerGo method)
FAIL	github.com/backtrace-labs/go-bcd [build failed]