Heroku with go and dep: `push rejected: failed to compile Go app`

Question

I am trying to deploy my Go Heroku app that uses dep to manage dependencies. However, when I attempt to push it, the logs say this.

Total 818 (delta 147), reused 0 (delta 0)
remote: Compressing source files... done.
remote: Building source:
remote: 
remote: -----> Go app detected
remote: -----> Fetching jq... done
remote: -----> Fetching tq... done
remote:  !!    
remote:  !!    Deprecated or unsupported version of go (go1.10.1)
remote:  !!    See https://devcenter.heroku.com/articles/go-support#go-versions for supported version information.
remote:  !!    
remote: -----> Installing go1.10.1
remote: -----> Fetching go1.10.1.linux-amd64.tar.gz... done
remote:  !!    Installing package '.' (default)
remote:  !!    
remote:  !!    To install a different package spec set 'metadata.heroku.pkg-spec' in 'Gopkg.toml'
remote:  !!    
remote:  !!    For more details see: https://devcenter.heroku.com/articles/go-apps-with-dep#build-configuration
remote:  !!    
remote: -----> Fetching dep... done
remote: -----> Fetching any unsaved dependencies (dep ensure)
remote: -----> Running: go install -v -tags heroku . 
remote: main.go:7:2: cannot find package "backend/database" in any of:
remote:         /tmp/tmp.2P0hB8CCKz/.go/src/main/vendor/backend/database (vendor tree)
remote:         /app/tmp/cache/go1.10.1/go/src/backend/database (from $GOROOT)
remote:         /tmp/tmp.2P0hB8CCKz/.go/src/backend/database (from $GOPATH)
remote: main.go:6:2: cannot find package "backend/user" in any of:
remote:         /tmp/tmp.2P0hB8CCKz/.go/src/main/vendor/backend/user (vendor tree)
remote:         /app/tmp/cache/go1.10.1/go/src/backend/user (from $GOROOT)
remote:         /tmp/tmp.2P0hB8CCKz/.go/src/backend/user (from $GOPATH)
remote:  !     Push rejected, failed to compile Go app.
remote: 
remote:  !     Push failed
remote: Verifying deploy...
remote: 
remote: !       Push rejected to thindan.
remote: 

It nags and complains about a GOPATH that is already correct on my system. I wonder why this is happening? My dep configuration file looks like this.

# Gopkg.toml example
#
# Refer to https://github.com/golang/dep/blob/master/docs/Gopkg.toml.md
# for detailed Gopkg.toml documentation.
#
# required = ["github.com/user/thing/cmd/thing"]
# ignored = ["github.com/user/project/pkgX", "bitbucket.org/user/project/pkgA/pkgY"]
#
# [[constraint]]
#   name = "github.com/user/project"
#   version = "1.0.0"
#
# [[constraint]]
#   name = "github.com/user/project2"
#   branch = "dev"
#   source = "github.com/myfork/project2"
#
# [[override]]
#  name = "github.com/x/y"
#  version = "2.4.0"


[[constraint]]
  name = "github.com/boltdb/bolt"
  version = "1.3.1"

[[constraint]]
  branch = "master"
  name = "golang.org/x/crypto"

[metadata.heroku]
root-package = "backend"
go-version = "1.10.1"
build = ["."]
ensure = "false"

What is wrong, and how can I fix it?

Answer 1

It looks like your import paths in

main.go:7:2: ==> "backend/database"

and

main.go:6:2: ==> "backend/user"

are not set correctly. Are you able to run your app locally? Are those two imports your own, user-defined packages? If so, please provide a schematic of your project directory structure. I am pretty sure fixing the import paths will fix the problem.

Answer 2

just in case someone still have the this problem, I fixed by specifying the following Gopkg.toml:

[metadata.heroku]
  root-package = "the-name-of-my-proyect"
  install = ["./..."]

in my case I didn't specify go version so it took the default one. Also I specified the install - ["./..."] because I have a monorepo in which the go code is in a sub folder