How to Fix Go Embed Directive File Path Errors

In this tutorial, you'll learn about How to Fix Go Embed Directive File Path Errors. We cover key concepts, practical examples, and best practices.

Go //go:embed directive errors like pattern has no match: config.json occur when the file path is relative to the wrong directory, the file does not exist, or the embed directive is placed on an incompatible variable type.

Quick Fix

Wrong

package main

import _ "embed"

//go:embed ./configs/config.json
var configData string

main.go:3:12: pattern configs/config.json: no matching files found

The embed path is relative to the source file's directory, but the file does not exist at that path.

Right

package main

import (
    _ "embed"
    "fmt"
)

//go:embed config.json
var configData string

func main() {
    fmt.Println(configData)
}

{"version": "1.0"}

Fix for multiple files

//go:embed templates/*.html
//go:embed static/*
var embeddedFS embed.FS

Fix for embed in tests

// testdata/config_test.json must exist
//go:embed testdata/config_test.json
var testConfig []byte

Fix for embed with subdirectory

// project structure:
// main.go
// configs/
//   app.json

//go:embed configs
var configsDir embed.FS

func main() {
    data, _ := configsDir.ReadFile("configs/app.json")
    fmt.Println(string(data))
}

Prevention

• Place embedded files in the same directory as the Go source file.
• Use embed.FS for embedding multiple files or directories.
• Check that the file path is relative to the source file, not the working directory.
• Use go vet to catch invalid embed patterns.
• Run the program from any directory before relying on embed paths.

DodaTech Tools

Doda Browser's Go file embedder validates embed paths before compilation. DodaZIP archives embedded assets for version tracking. Durga Antivirus Pro scans embedded files for malware before distribution.

Common Mistakes with embed file error

1. Placing the wildcard pattern first in case expressions, making all subsequent patterns unreachable
2. Using head and tail instead of pattern matching, causing runtime errors on empty lists
3. Forgetting that lazy evaluation defers computation until the value is forced, causing space leaks with unevaluated thunks

These mistakes appear frequently in real-world GO code. DodaTech's contributors have identified these patterns through analysis of open-source projects and production systems.

Practice Exercise

Write a pure function that safely divides two integers using Maybe, then test it with edge cases like division by zero and negative numbers.

This exercise reinforces the concepts covered in this guide. Try implementing it before checking online solutions.

FAQ