What steps will reproduce the problem?

add panic("BOOM") to package foo and test package bar that uses foo. I want to
use go test -c because I actually want to do sudo bar.test.

$ go test -c && sudo ./bar.test
warning: building out-of-date packages:
        foo
installing these packages with 'go test -i' will speed future tests.

panic: BOOM

change foo to emit panic ARGH and try to do what the tool tells me

$ go test -i -c && sudo ./bar.test

panic: BOOM

my -c was ignored

$ go test -c && ./server.test

panic: ARGH

What is the expected output?

go test -i -c should also build and overwrite the test

Which compiler are you using (5g, 6g, 8g, gccgo)?

6g

Which operating system are you using?

linux

Which revision are you using?  (hg identify)

close to tip