When I enable gomodules and build my go program then the required packages are downloaded.
But I cannot find them in $GOPATH/src/ or in $GOPATH/s
$GOPATH/src/
$GOPATH/s
In case you want clean up cache there is a command go clean --modcache
go clean --modcache
In case you just need to update some dependency you probably want to clean up information about this dependency from