Received “cannot execute binary file: Exec format error” while pushing golang project to heroku. Why is this happening?

Question

I have been recently attempting to deploy a simple golang app to heroku using the same method I used to deploy previous ones, and I'm running into error with my procfile execution.

2021-07-06T23:30:28.000000+00:00 app[api]: Build started by user user@yahoo.com
2021-07-06T23:30:40.271575+00:00 app[api]: Release v7 created by user user@yahoo.com
2021-07-06T23:30:40.271575+00:00 app[api]: Deploy 0d19e552 by user user@yahoo.com
2021-07-06T23:30:40.909377+00:00 heroku[web.1]: State changed from crashed to starting
2021-07-06T23:30:42.049118+00:00 heroku[web.1]: Starting process with command `bin/main`
2021-07-06T23:30:45.582197+00:00 app[web.1]: bash: bin/main: cannot execute binary file: Exec format error
2021-07-06T23:30:45.646220+00:00 heroku[web.1]: Process exited with status 126
2021-07-06T23:30:45.722720+00:00 heroku[web.1]: State changed from starting to crashed
2021-07-06T23:30:57.000000+00:00 app[api]: Build succeeded

2021-07-06T23:45:41.986316+00:00 heroku[router]: at=error code=H10 desc="App crashed" method=GET path="/" host=testing-my-message-app.herokuapp.com request_id=fd3a8259-82dc-489f-b206-060ec0d8f8f6 fwd="67.81.209.179" dyno= connect= service= status=503 bytes= protocol=https      
2021-07-06T23:45:42.522223+00:00 heroku[router]: at=error code=H10 desc="App crashed" method=GET path="/favicon.ico" host=testing-my-message-app.herokuapp.com request_id=f3268609-cdcc-4c16-af24-f7dfa5568030 fwd="67.81.209.179" dyno= connect= service= status=503 bytes= protocol=https

I tried running both go build -o bin/main and go build -o bin/main -v . to build the binary file, but heroku is unable to build it for due to format error. How can I fix this? I'm running on a 64 bit window platform for reference.

Also, just in case, here is the code I am trying to deploy.

package main

import (
    "fmt"
    "log"
    "net/http"
    "os"
    "strconv"

    "github.com/go-chi/chi"
    "github.com/go-chi/render"
    "github.com/joho/godotenv"
)

type m map[string]interface{}

func main(){
    godotenv.Load()

    router := chi.NewRouter()
    words := m{
        "black": 10,
        "red": 7,
        "pink": 0,
        "yellow": 5,
        "blue": 9,
    }

    router.Get("/all", func(res http.ResponseWriter, req *http.Request) {
        render.JSON(res, req, words)
    })

    router.Get("/add-color-rating/{color}/{rating}", func(res http.ResponseWriter, req *http.Request) {
        color  := chi.URLParam(req, "color")
        rating, _ := strconv.Atoi(chi.URLParam(req, "rating"))

        words[color] = rating
        render.JSON(res, req, m{"added-rating": m{color: rating}})
    })
    
    fs := http.FileServer(http.Dir("./static"))
    router.Handle("/static/*", http.StripPrefix("/static", fs))

    fmt.Println("running on port:", os.Getenv("PORT"))
    log.Fatal(http.ListenAndServe(os.Getenv("PORT"), router))
}

Answer 1

If youre trying to build files in the bin/main folder, you need to do this:

go build bin/main

If you are trying to build in the current folder, you need to do this:

go build -o bin/main.exe

https://golang.org/cmd/go#hdr-Compile_packages_and_dependencies

Answer 2

It could also be that you are trying to run an executable compiled for a specific architecture on a platform with a different architecture. Try specifying the the target os and architecture in which you expect to run the build as follows.

env GOOS=linux GOARCH=arm64 go build -o bin/main