I am trying to learn how to build a webserver using go and mux. I am importing mux to the main.go file as import github.com/gorilla/mux. However, when I am trying to run the code. I get the following error
no required module provides package github.com/gorilla/mux: go.mod file not found in current directory or any parent directory; see 'go help modules'
My GOPATH is /Users/michiokaku/Study/go
The overall structure of my directories is
go___
pkg
bin
my_codes___
main.go
Inside pkg, I found a directory named mux#v1.8.0 in the path pkg/mod/github.com/gorilla. I think this is what I downloaded using go get -u github.com/gorilla/mux. But when the code is running, I am getting errors.
What is the issue here? How do I solve this?
PS: I am using mac.
Read through Tutorial: Getting Started with Go, if you haven't seen it already. It matches your situation pretty closely.
In short:
Run go mod init example.com/projectname, replacing the last argument with the name for your module. This will create a go.mod file in the current directory that will track your dependencies. Your module's name will be a prefix for all packages within your module.
Run go mod tidy or go get github.com/gorilla/mux to add github.com/gorilla/mux as a dependency.
You mentioned you saw a directory pkg/mod/github.com/gorilla earlier. This is part of Go's module cache, shared by all projects.
Related
I am new to go and have trouble using a library that does not have a go.mod file. The library is https://github.com/yourbasic/graph and I tried installing it according to the instructions given in the go docs. Since I cannot make a request for the version on the repo, I used the #latest flag, so in order to install, I executed
go install github.com/yourbasic/graph#latest
This however fails and says
package github.com/yourbasic/graph is not a main package
Is there a proper way to install libraries like that? I assume my way of proceeding to just copy the files into a directory within my project is not very clean.
As #JimB said: instead of attempting to install it,
Import the package in your code where applicable.
Run go get github.com/yourbasic/graph#latest — which will download the module (to the local cache) and update your module's go.mod file.
Build.
The steps 1 and 2 can be swapped, but then the generated go.mod entry will have the // indirect comment which will disappear next time you run go mod tidy.
I'm trying to play around with the lightning network. I have cloned the repo, and on disk placed it here (I'm using windows):
C:\Users\hallibut\Documents\GitHub\lnd
I'd like to run any of the tests in itest, lets say testMultiHopPayments. The cli commands I'm using after I cd into the above location is:
go test itest -run testMultiHopPayments
However, I keep getting the error:
package itest is not in GOROOT (C:\Program Files\Go\src\itest)
I've read through the various posts on this error, but I'm still not quite sure why it happens, and it's likely because I don't fully understand the go module (I'm new to go). This article, was probably the best in helping me understand the structure and env variables:
https://golangbyexample.com/workspace-hello-world-golang/
My understanding from the various readings is that whatever directory the go.mod file is in, indicates the module level directory. Prior to version 1.13 there was a required directory and structure, but now that should not be an issue if you're using at least version 1.13 and modules. I'm using 1.17.1. This is somewhat of an assumption or inference, but I believe everything lower in the directory structure is part of a package to be installed as part of the module (and is defined by the package keyword). However, I don't understand why a package with source code within a subdirectory would be missing/throw the aforementioned error. I've also tried running:
go mod install github.com/lightningnetwork/lnd/lntest/itest
That doesn't seem to do anything/has not effect on the error. What am I not understanding about packages? Looking at the go.mod file I observe that itest is not specifically defined anywhere… Not sure if that's required. Also, I assume I've got to run some build process prior? I attempted this with:
go install -v ./...
If you're using VS Code and Go Modules, you need to "Open folder" and point to the cloned repo, to get around that error
Converting an existing project with a /vendor directory to use Go Modules (go version 1.12). I do go mod init to generate the go.mod file. Then I do go get -u ./... to populate the go.mod file. During this time, it tries to locate a package on github that no longer exists. It is vendored in my /vendor directory.
Until I can upgrade my code to use a different package, how can I continue the conversion to using modules? That is, I want to keep some things vendored (I also have some modified code under /vendor), while other things are handled by go modules.
You can't mix the vendor directory behavior and modules, each method of dependency resolution precludes the other. You can re-publish the missing package yourself somewhere that go mod can locate it, or you can redirect it directly to the existing vendored source in your module.
To redirect the source of a module, use the replace directive in the go.mod file
replace missing/package v0.0.1 => ./vendor/missing/package
go version go1.11.4 darwin/amd64
GOPATH has been unset but was previously set to $HOME/Development/go
Project path is under $HOME/code/
I’m able to successfully (no errors at least) install the go-sql-driver/mysql package using the command
go get github.com/go-sql-driver/mysql#v1
When I include a reference to that package in an import statement
import(
_ "github.com/go-sql-driver/mysql")
in my code I see the error
could not import github.com/go-sql-driver/mysql (can’t find import:
“github.com/go-sql-driver/mysql”)
I have run go mod init in my project root and it creates a go.mod file. When I run the go get command I see a require statement added to that file for the package. But it seems the files for the package get installed in the default $HOME/go directory (since I've unset GOPATH).
Should I be doing things differently so that my import statement can find the newly installed package? Using modules shouldn't all the packages be installed in the project path somewhere?
Should I be doing things differently so that my import statement can find the newly installed package?
No. With modules there is no need to install the packages upfront at all.
Using modules shouldn't all the packages be installed in the project path somewhere?
No. They get downloaded somewhere in some format and used from that location but they are not "installed" like in the old GOPATH variant of go get.
Show output of go env and what go mod vendor produces.
I'm pretty sure I was doing things wrong. I was able to resolve this after referencing the following closely the steps documented at golang modules wiki. The summary is that there is no need to "install" a package via 'go get'. Instead simply make sure your project is initialized to use modules using the 'go mod init' command and then include the package name in an import statement. The next build event will pull down the package and all its dependencies.
Here is the error message:
% go get
can't load package: package .: no buildable Go source files in /Users/7yan00
% echo $GOPATH
/Users/7yan00/Golang
How would you troubleshoot that error?
Make sure you are using that command in the Go project source folder (like /Users/7yan00/Golang/src/myProject).
One alternative (similar to this bug) is to use the -d option (see go get command)
go get -d
The -d flag instructs get to stop after downloading the packages; that is, it instructs get not to install the packages.
See if that helps in your case.
But more generally, as described in this thread:
go get is for package(s), not for repositories.
so if you want a specific package, say, go.text/encoding, then use
go get code.google.com/p/go.text/encoding
if you want all packages in that repository, use ... to signify that:
go get code.google.com/p/go.text/...
You should check the $GOPATH directory. If there is an empty directory of the package name, go get doesn't download the package from the repository.
For example, If I want to get the github.com/googollee/go-socket.io package from it's github repository, and there is already an empty directory github.com/googollee/go-socket.io in the $GOPATH, go get doesn't download the package and then complains that there is no buildable Go source file in the directory. Delete any empty directory first of all.
Another possible reason for the message:
can't load package: .... : no buildable Go source files
Is when the source files being compiled have:
// +build ignore
In which case the files are ignored and not buildable as requested.This behaviour is documented at https://golang.org/pkg/go/build/
To resolve this for my situation:
I had to specify a more specific sub-package to install.
Wrong:
go get github.com/garyburd/redigo
Correct:
go get github.com/garyburd/redigo/redis
If you want all packages in that repository, use ... to signify that, like:
go get code.google.com/p/go.text/...
you can try to download packages from mod
go get -v all
I had this exact error code and after checking my repository discovered that there were no go files but actually just more directories. So it was more of a red herring than an error for me.
I would recommend doing
go env
and making sure that everything is as it should be, check your environment variables in your OS and check to make sure your shell (bash or w/e ) isn't compromising it via something like a .bash_profile or .bashrc file. good luck.