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.
Related
I am using an open source project called "yaegi" in a large project.
I need to use older version of "yaegi": v.0.8.11, so I modified the go.mod file and replaced:
github.com/traefik/yaegi v0.9.2 // indirect with github.com/containous/yaegi v0.8.11
But when I build the project, it starts to update all the modules and replace it back to the most updated version:
root#ubuntu:~/myproj1# go build main.go
go: finding module for package github.com/traefik/yaegi/stdlib/unsafe
go: finding module for package github.com/traefik/yaegi/stdlib
go: finding module for package github.com/traefik/yaegi/interp
go: found github.com/traefik/yaegi/interp in github.com/traefik/yaegi v0.9.2
How can I prevent it and keep it using the old version v.0.8.11?
I read that according to https://tip.golang.org/cmd/go/#hdr-Maintaining_module_requirements:
The go command itself automatically updates the go.mod file to maintain a standard formatting and the accuracy of require statements.
Any go command that finds an unfamiliar import will look up the module containing that import and add the latest version of that module to go.mod automatically. […]
Any go command can determine that a module requirement is missing and must be added […].
Maybe there is a way to bypass it?
//indirect in go.mod means that at least one of your other modules you’re importing is dependent on that version of module, therefore go build shall automatically update that module, no matter how you changed that line in your go.mod. In your case if you don’t want to use yaegi module of v0.9.2 you have to first get rid of other dependencies dependent on that module from your project, and then fix your go.mod to make your project require yaegi v0.8.11. You can just delete them or make them require earlier version of yaegi by using their older version or editing their source code. Also, instead of editing go.mod directly, I’d run something like go get -v github.com/containous/yaegi#0.8.11 to checkout to a specific version of a module.
I'm a bit confused about how Go modules work on installing binaries using go install.
I tried to install (https://github.com/joho/godotenv) binary by executing go install github.com/joho/godotenv/cmd/godotenv and I found out that it adds a record in the go.mod.
I'm lost as we don't use this package in the code and after running go mod tidy it gets deleted (as it is not it the code).
Can someone explain is it expected behaviour of go modules?
Secondly, how I could avoid adding it to the go.mod as we only need to install and execute the binary?
Thanks.
Go version: go version go1.13.4 darwin/amd64
Command go: The go.mod file:
The go command automatically updates go.mod each time it uses the module graph, to make sure go.mod always accurately reflects reality and is properly formatted.
The go tool will update go.mod automatically when it detects dependencies are inaccurate when performing a build.
When you install github.com/joho/godotenv/cmd/godotenv from your module, this install requires at least the package in question being built / installed (and also its dependencies, transitively).
You may safely run go mod tidy to undo the recording of this "one-time" dependency.
In general if you want to disallow the go tool to update the go.mod file, you may use the -mod=readonly flag, but that would fail go install ("can't load package: package xxx: import lookup disabled by -mod=readonly"). You can read more about this here: Go Wiki: Go modules: Can I control when go.mod gets updated and when the go tools use the network to satisfy dependencies?
Alternatively, if you want to avoid this, build / install your tools outside of your module. You may use a "dummy" module for this.
I've installed a package using go modules (go get in Go 1.13) and now I want to remove it. In the documentation there is nothing about this and in go get docu neither.
Removing the package from go.mod manually doesn't solve the issue so it remains in go.sum.
How should I remove a package in a clean way?
Found it https://go.dev/blog/using-go-modules#removing-unused-dependencies
go mod tidy
So basically, once the package is not being imported in any package you can perform a go mod tidy and it will safely remove the unused dependencies.
And if you are vendoring the dependencies, then run the command below to make the module changes be applied in the vendor folder:
go mod vendor
#jesugmz answer doesn't say, what if you wanna remove a currently using package in go modules.
So, if you're using go modules (you have a go.mod file in your project) and you want to remove a currently using package, check $GOPATH/pkg/mod/ directory and simply remove the package named package#version.
For example, if you have github.com/some/project package installed, you should run the following command:
rm -rf $(go env GOPATH)/pkg/mod/github.com/some/project#v1.0.0
You can find the using package version in go.mod file.
I’m trying to figure out if it’s possible to run go mod vendor without the go tool updating my go.mod file.
I specifically go get package/subpackage#commit and commit my go.mod with the correct version.
Then I run go mod vendor and it automatically bumps the version of the package that I just specifically set.
I’ve looked at this page to no avail: https://github.com/golang/go/wiki/Modules#how-do-i-use-vendoring-with-modules-is-vendoring-going-away
I need to use vendor because I run a script that edits some of the vendored deps., I’m looking at the following build flow:
GO111MODULE=on go get package/subpackge#commit
GO111MODULE=on go mod vendor
./Script/patch_vendors.sh --write
GO111MODULE=off go build
My other option is modifying the copied source wherever go mod vendor donwloads it to, but
not sure how to approach that.
Thanks in advance
Per https://tip.golang.org/cmd/go/#hdr-Maintaining_module_requirements:
The go command itself automatically updates the go.mod file to maintain a standard formatting and the accuracy of require statements.
Any go command that finds an unfamiliar import will look up the module containing that import and add the latest version of that module to go.mod automatically. […]
Any go command can determine that a module requirement is missing and must be added […].
The go mod vendor command copies in all of the transitive imports of your packages and their tests, so it will automatically update the go.mod file to ensure that all of the imported packages are present.
So the problem here is likely that the commit you've selected for package/subpackage fails to provide some package that appears in the transitive imports of your program. If that is correct, you should find that go list all, go test all, and go mod tidy all make that same edit to your module's requirements.
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.