go get vs go install on go.sum file

I'm using go 1.20.3

I've just install this packages with go get and go install

go get -v github.com/mactsouk/go/simpleGitHub
go install  github.com/mactsouk/go/simpleGitHub

what i have on my go.sum file is:

github.com/mactsouk/go v0.0.0-20180603081621-6a282087f7bd h1:TqJGx/jAxlJ3RNL7pS7XZQlvtH8rL/dUsA8wPe9W4y0=
github.com/mactsouk/go v0.0.0-20180603081621-6a282087f7bd/go.mod h1:TRtlPc1xi1zOQdbA/cIxGdS+fCaIZDQUpMrFlET5dbI=

and on the go.mod file is:

module calculator

go 1.20

require github.com/mactsouk/go v0.0.0-20180603081621-6a282087f7bd // indirect

aod on my $Home/go/pkg/mod/github.com/mactsouk/

dr-xr-xr-x  5 user  staff  160 Jul  4 18:42 go@v0.0.0-20180603081621-6a282087f7bd

and nothing on $Home/go/bin/ but two files, why go install did not copied binary files for simpleGitHub module ?

drwxr-xr-x  4 user  staff       128 Jun 26 23:37 .
drwxr-xr-x  4 user  staff       128 Jun 26 23:35 ..
-rwxr-xr-x  1 user  staff   3410064 Jun 26 23:35 go-outline
-rwxr-xr-x  1 user  staff  28237216 Jun 26 23:37 gopls

there are differences between go get and go install ? why i have on go.sum files this module twice ?

go get vs go install

The go get and go install commands in Go serve different purposes:

go get is used to retrieve and download packages and their dependencies from remote repositories. It updates the go.mod and go.sum files with the versions of the downloaded packages. If the package is already present, go get will update it to the latest version.

go install compiles and installs the package in your project's GOPATH or GOBIN. It does not update the go.mod or go.sum files. Instead, it uses the information in those files to determine the correct versions of the dependencies to use.

In your case, when you ran go get, it downloaded and installed the package github.com/mactsouk/go/simpleGitHub and its dependencies. This action updated the go.mod and go.sum files with the versions of the downloaded packages.

When you subsequently ran go install for the same package, it didn't need to download the package again because it was already present in your local Go module cache. Therefore, go install used the existing package and its version from the cache, and it didn't modify the go.mod or go.sum files.

The reason you see the module listed twice in the go.sum file is because it contains both the module version (v0.0.0-20180603081621-6a282087f7bd) and its corresponding go.mod file with a checksum. This is the expected behavior and ensures the integrity of the dependencies.

To summarize, go get and go install have different purposes, and the duplication of the module in the go.sum file is normal.