The go test flag: flag provided but not defined error is raised when you’ve provided a command-line flag to go test that it doesn’t recognize. This error message usually occurs when you try to use a flag that has not been defined. One possible reason for this error is that you are using an outdated version of Go.
To fix this error, you can use the var _ = func() bool { testing.Init(); return true }() as a possible workaround which would call test initialization before the application one.
You can view the list of flags supported by go test by running:
go help testflag
If you are trying to pass flags to the test binary itself, rather than go test, you need to use the -args flag to separate the flags intended for the test binary.
Here’s an example:
go test -v -args -my_custom_flag=value
In this example, -v is a flag for the go test, while -my_custom_flag is a flag for the test binary.
The -args flag tells the go test that the following flags should be passed to the test binary.
Ensure you are using the correct flags and syntax when running the go test.
That’s it.

Krunal Lathiya is a Software Engineer with over eight years of experience. He has developed a strong foundation in computer science principles and a passion for problem-solving. In addition, Krunal has excellent knowledge of Distributed and cloud computing and is an expert in Go Language.