go-delve/delve · error

not implemented

Error message

not implemented

What it means

Follow-exec mode (debugging child processes after fork/exec) is implemented only on Linux; on other platforms detachChild on processGroup panics with 'not implemented', and FollowExec returns a plain error. The panic surfaces if the cross-platform code path calls add() which tries to detach a child on a backend that can't create one.

Source

Thrown at pkg/proc/native/followexec_other.go:13

//go:build !linux && !windows

package native

import "errors"

// FollowExec enables (or disables) follow exec mode
func (*nativeProcess) FollowExec(bool) error {
	return errors.New("follow exec not implemented")
}

func (*processGroup) detachChild(*nativeProcess) error {
	panic("not implemented")
}

View on GitHub (pinned to a23773e6c3)

Solutions

1. Use follow-exec only on Linux
2. Check runtime.GOARCH/GOOS before enabling FollowExec in tooling
3. For other OSes, handle the FollowExec error return instead of reaching detachChild
4. Track upstream porting notes for follow-exec on other platforms

Example fix

// before
grp.add(child)
// after
if runtime.GOOS != "linux" {
    return errors.New("follow exec not supported on " + runtime.GOOS)
}
grp.add(child)

if runtime.GOOS != "linux" {
    return errors.New("follow exec only supported on linux")
}

if err := grp.FollowExec(true); err != nil {
    // followexec_other.go returns a clear error here
    return err
}

When it happens

Trigger: Calling processGroup.add (or enabling follow-exec) on a non-Linux OS (windows, darwin, freebsd) where followexec_other.go's stub is compiled in.

Common situations: Using delve's follow-exec feature on macOS/Windows; embedding pkg/proc/native in a tool that calls detachChild outside Linux; tests exercising process-group logic portably.

Related errors

• follow exec not supported
• follow exec not implemented
• could not get panic: %v
• unknown argument %q to 'target follow-exec'
• unknown argument %q to 'target follow-exec'

AI-assisted analysis of go-delve/delve@a23773e6c3 (2026-08-31). Data as JSON: /api/errors/39e3d923d85a97e1. Report an issue: GitHub.